Science.gov

Sample records for environmental masking noise

  1. Development of computer program ENMASK for prediction of residual environmental masking-noise spectra, from any three independent environmental parameters

    SciTech Connect

    Chang, Y.-S.; Liebich, R. E.; Chun, K. C.

    2000-03-31

    Residual environmental sound can mask intrusive4 (unwanted) sound. It is a factor that can affect noise impacts and must be considered both in noise-impact studies and in noise-mitigation designs. Models for quantitative prediction of sensation level (audibility) and psychological effects of intrusive noise require an input with 1/3 octave-band spectral resolution of environmental masking noise. However, the majority of published residual environmental masking-noise data are given with either octave-band frequency resolution or only single A-weighted decibel values. A model has been developed that enables estimation of 1/3 octave-band residual environmental masking-noise spectra and relates certain environmental parameters to A-weighted sound level. This model provides a correlation among three environmental conditions: measured residual A-weighted sound-pressure level, proximity to a major roadway, and population density. Cited field-study data were used to compute the most probable 1/3 octave-band sound-pressure spectrum corresponding to any selected one of these three inputs. In turn, such spectra can be used as an input to models for prediction of noise impacts. This paper discusses specific algorithms included in the newly developed computer program ENMASK. In addition, the relative audibility of the environmental masking-noise spectra at different A-weighted sound levels is discussed, which is determined by using the methodology of program ENAUDIBL.

  2. Zero-dimensional noise: the best mask you never saw.

    PubMed

    Baker, Daniel H; Meese, Tim S

    2012-09-29

    The transmission of weak signals through the visual system is limited by internal noise. Its level can be estimated by adding external noise, which increases the variance within the detecting mechanism, causing masking. But experiments with white noise fail to meet three predictions: (a) noise has too small an influence on the slope of the psychometric function, (b) masking occurs even when the noise sample is identical in each two-alternative forced-choice (2AFC) interval, and (c) double-pass consistency is too low. We show that much of the energy of 2D white noise masks extends well beyond the pass-band of plausible detecting mechanisms and that this suppresses signal activity. These problems are avoided by restricting the external noise energy to the target mechanisms by introducing a pedestal with a mean contrast of 0% and independent contrast jitter in each 2AFC interval (termed zero-dimensional [0D] noise). We compared the jitter condition to masking from 2D white noise in double-pass masking and (novel) contrast matching experiments. Zero-dimensional noise produced the strongest masking, greatest double-pass consistency, and no suppression of perceived contrast, consistent with a noisy ideal observer. Deviations from this behavior for 2D white noise were explained by cross-channel suppression with no need to appeal to induced internal noise or uncertainty. We conclude that (a) results from previous experiments using white pixel noise should be re-evaluated and (b) 0D noise provides a cleaner method for investigating internal variability than pixel noise. Ironically then, the best external noise stimulus does not look noisy.

  3. Propagation of Environmental Noise

    ERIC Educational Resources Information Center

    Lyon, R. H.

    1973-01-01

    Solutions for environmental noise pollution lie in systematic study of many basic processes such as reflection, scattering, and spreading. Noise propagation processes should be identified in different situations and assessed for their relative importance. (PS)

  4. Does Masking Matter? Shipping Noise and Fish Vocalizations.

    PubMed

    Neenan, Sarah T V; Piper, Rayner; White, Paul R; Kemp, Paul; Leighton, Timothy G; Shaw, Peter J

    2016-01-01

    Shipping creates large near-field background noises at levels similar to or higher than fish vocalizations and in the same critical bandwidths. This noise has the potential to "mask" biologically important signals and prevent fish from hearing them; any interference with the detection and recognition of sounds may impact fish survival. The Lombard effect, whereby vocalizations are altered to reduce or exclude masking effects, is an adaptation that has been observed in mammals and birds. Research is needed to establish whether the Lombard effect occurs in fish to gain a better understanding of the implications of noise pollution on fish populations.

  5. Effect of contralateral white noise masking on the mismatch negativity.

    PubMed

    Salo, S K; Lang, A H; Salmivalli, A J

    1995-01-01

    Mismatch negativity (MMN), an auditive event-related potential (ERP) component, evoked by deviant stimuli in a homogeneous stream of standard stimuli was studied in a unilateral stimulation and contralateral white noise masking condition. Eleven subjects (Ss) with normal hearing (aged 20-35 years) were examined using sine tone stimuli (70 dB HL, interstimulus interval 300 ms, duration 40 ms with 5 ms rise and fall times). Three blocks of standard (std)/deviant (dev) series of stimuli were used: std 500/dev 600 Hz, std 2000/dev 1900 Hz, and std 2000/dev 1600 Hz. The first block was repeated for another group of 11 Ss with normal hearing (aged 17-27 years). The MMN was analysed from the difference curves recorded at Fz, Cz and Pz. The stimuli were delivered unilaterally, either with or without 50 dB effective masking level white noise to the contralateral ear. The MMN amplitude attenuated significantly when contralateral masking was used. In addition, there was interaction between noise masking and the stimulated ear. The MMN latencies were not affected by white noise masking.

  6. Study on achieving speech privacy using masking noise

    NASA Astrophysics Data System (ADS)

    Tamesue, Takahiro; Yamaguchi, Shizuma; Saeki, Tetsuro

    2006-11-01

    This study focuses on achieving speech privacy using a meaningless steady masking noise. The most effective index for achieving a satisfactory level of speech privacy was selected, choosing between spectral distance and the articulation index. From a result, spectral distance was selected as the best and most practical index for achieving speech privacy. Next, speech along with a masking noise with a sound pressure level value corresponding to various speech privacy levels were presented to subjects who judged the psychological impression of the particular speech privacy level. Theoretical calculations were in good agreement with the experimental results.

  7. Control of Environmental Noise

    ERIC Educational Resources Information Center

    Jensen, Paul

    1973-01-01

    Discusses the physical properties, sources, physiological effects, and legislation pertaining to noise, especially noise characteristics in the community. Indicates that noise reduction steps can be taken more intelligently after determination of the true noise sources and paths. (CC)

  8. Perceptual effects of noise reduction by time-frequency masking of noisy speech.

    PubMed

    Brons, Inge; Houben, Rolph; Dreschler, Wouter A

    2012-10-01

    Time-frequency masking is a method for noise reduction that is based on the time-frequency representation of a speech in noise signal. Depending on the estimated signal-to-noise ratio (SNR), each time-frequency unit is either attenuated or not. A special type of a time-frequency mask is the ideal binary mask (IBM), which has access to the real SNR (ideal). The IBM either retains or removes each time-frequency unit (binary mask). The IBM provides large improvements in speech intelligibility and is a valuable tool for investigating how different factors influence intelligibility. This study extends the standard outcome measure (speech intelligibility) with additional perceptual measures relevant for noise reduction: listening effort, noise annoyance, speech naturalness, and overall preference. Four types of time-frequency masking were evaluated: the original IBM, a tempered version of the IBM (called ITM) which applies limited and non-binary attenuation, and non-ideal masking (also tempered) with two different types of noise-estimation algorithms. The results from ideal masking imply that there is a trade-off between intelligibility and sound quality, which depends on the attenuation strength. Additionally, the results for non-ideal masking suggest that subjective measures can show effects of noise reduction even if noise reduction does not lead to differences in intelligibility.

  9. What Do Contrast Threshold Equivalent Noise Studies Actually Measure? Noise vs. Nonlinearity in Different Masking Paradigms.

    PubMed

    Baldwin, Alex S; Baker, Daniel H; Hess, Robert F

    2016-01-01

    The internal noise present in a linear system can be quantified by the equivalent noise method. By measuring the effect that applying external noise to the system's input has on its output one can estimate the variance of this internal noise. By applying this simple "linear amplifier" model to the human visual system, one can entirely explain an observer's detection performance by a combination of the internal noise variance and their efficiency relative to an ideal observer. Studies using this method rely on two crucial factors: firstly that the external noise in their stimuli behaves like the visual system's internal noise in the dimension of interest, and secondly that the assumptions underlying their model are correct (e.g. linearity). Here we explore the effects of these two factors while applying the equivalent noise method to investigate the contrast sensitivity function (CSF). We compare the results at 0.5 and 6 c/deg from the equivalent noise method against those we would expect based on pedestal masking data collected from the same observers. We find that the loss of sensitivity with increasing spatial frequency results from changes in the saturation constant of the gain control nonlinearity, and that this only masquerades as a change in internal noise under the equivalent noise method. Part of the effect we find can be attributed to the optical transfer function of the eye. The remainder can be explained by either changes in effective input gain, divisive suppression, or a combination of the two. Given these effects the efficiency of our observers approaches the ideal level. We show the importance of considering these factors in equivalent noise studies.

  10. What Do Contrast Threshold Equivalent Noise Studies Actually Measure? Noise vs. Nonlinearity in Different Masking Paradigms

    PubMed Central

    Baldwin, Alex S.; Baker, Daniel H.; Hess, Robert F.

    2016-01-01

    The internal noise present in a linear system can be quantified by the equivalent noise method. By measuring the effect that applying external noise to the system’s input has on its output one can estimate the variance of this internal noise. By applying this simple “linear amplifier” model to the human visual system, one can entirely explain an observer’s detection performance by a combination of the internal noise variance and their efficiency relative to an ideal observer. Studies using this method rely on two crucial factors: firstly that the external noise in their stimuli behaves like the visual system’s internal noise in the dimension of interest, and secondly that the assumptions underlying their model are correct (e.g. linearity). Here we explore the effects of these two factors while applying the equivalent noise method to investigate the contrast sensitivity function (CSF). We compare the results at 0.5 and 6 c/deg from the equivalent noise method against those we would expect based on pedestal masking data collected from the same observers. We find that the loss of sensitivity with increasing spatial frequency results from changes in the saturation constant of the gain control nonlinearity, and that this only masquerades as a change in internal noise under the equivalent noise method. Part of the effect we find can be attributed to the optical transfer function of the eye. The remainder can be explained by either changes in effective input gain, divisive suppression, or a combination of the two. Given these effects the efficiency of our observers approaches the ideal level. We show the importance of considering these factors in equivalent noise studies. PMID:26953796

  11. Clinical masking with tragal rubbing and the Bárány noise-box.

    PubMed

    Swan, I R

    1989-12-01

    When assessing hearing by free-field voice testing, it is essential to mask the non-test ear. An appropriate method of masking must be chosen to suit the stimulus used. This study demonstrates that tragal rubbing is an effective means of masking a whispered or conversational voice, but a Bárány noise-box is required to mask a loud voice. However, a Bárány noise-box should not be used routinely as it is likely to overmask a normal or mildly impaired ear.

  12. Vowel perception by noise masked normal-hearing young adults

    NASA Astrophysics Data System (ADS)

    Richie, Carolyn; Kewley-Port, Diane; Coughlin, Maureen

    2005-08-01

    This study examined vowel perception by young normal-hearing (YNH) adults, in various listening conditions designed to simulate mild-to-moderate sloping sensorineural hearing loss. YNH listeners were individually age- and gender-matched to young hearing-impaired (YHI) listeners tested in a previous study [Richie et al., J. Acoust. Soc. Am. 114, 2923-2933 (2003)]. YNH listeners were tested in three conditions designed to create equal audibility with the YHI listeners; a low signal level with and without a simulated hearing loss, and a high signal level with a simulated hearing loss. Listeners discriminated changes in synthetic vowel tokens /smcapi e ɛ invv æ/ when F1 or F2 varied in frequency. Comparison of YNH with YHI results failed to reveal significant differences between groups in terms of performance on vowel discrimination, in conditions of similar audibility by using both noise masking to elevate the hearing thresholds of the YNH and applying frequency-specific gain to the YHI listeners. Further, analysis of learning curves suggests that while the YHI listeners completed an average of 46% more test blocks than YNH listeners, the YHI achieved a level of discrimination similar to that of the YNH within the same number of blocks. Apparently, when age and gender are closely matched between young hearing-impaired and normal-hearing adults, performance on vowel tasks may be explained by audibility alone.

  13. Temporal phase mask encrypted optical steganography carried by amplified spontaneous emission noise.

    PubMed

    Wu, Ben; Wang, Zhenxing; Shastri, Bhavin J; Chang, Matthew P; Frost, Nicholas A; Prucnal, Paul R

    2014-01-13

    A temporal phase mask encryption method is proposed and experimentally demonstrated to improve the security of the stealth channel in an optical steganography system. The stealth channel is protected in two levels. In the first level, the data is carried by amplified spontaneous emission (ASE) noise, which cannot be detected in either the time domain or spectral domain. In the second level, even if the eavesdropper suspects the existence of the stealth channel, each data bit is covered by a fast changing phase mask. The phase mask code is always combined with the wide band noise from ASE. Without knowing the right phase mask code to recover the stealth data, the eavesdropper can only receive the noise like signal with randomized phase.

  14. The masking of beluga whale (Delphinapterus leucas) vocalizations by icebreaker noise

    NASA Astrophysics Data System (ADS)

    Erbe, Christine

    1998-11-01

    This thesis examines the masking effect of underwater noise on beluga whale communication. As ocean water is greatly opaque for light but well conducting for sound, marine mammals rely primarily on their hearing for orientation and communication. Man-made underwater noise has the potential of interfering with sounds used by marine mammals. Masking to the point of incomprehensibility can have fatal results-for the individual, but ultimately for the entire species. As part of our understanding of whether marine mammals can cope with human impact on nature, this thesis is the first to study the interference of real ocean noises with complex animal vocalizations. At the Vancouver Aquarium, a beluga whale was trained for acoustic experiments, during which masked hearing thresholds were measured. Focus lay on noise created by icebreaking ships in the Arctic. As experiments with trained animals are time and cost expensive, various techniques were examined for their ability to model the whale's response. These were human hearing tests, visual spectrogram discrimination, matched filtering, spectrogram cross-correlation, critical band cross-correlation, adaptive filtering and various types of artificial neural networks. The most efficient method with respect to similarity to the whale's data and speed, was a backpropagation neural net. Masked hearing thresholds would be of little use if they could not be related to accessible quantities in the wild. An ocean sound propagation model was applied to determine critical distances between a noise source, a calling whale and a listening whale. Colour diagrams, called maskograms, were invented to illustrate zones of masking in the wild. Results are that bubbler system noise with a source level of 194 dB re 1 μPa at 1 m has a maximum radius of masking of 15 km in a 3- dimensional ocean. Propeller noise with a source level of 203 dB re 1 μPa at 1 m has a maximum radius of masking of 22 km. A naturally occurring icecracking event

  15. Auditory Masking Patterns in Bottlenose Dolphins from Anthropogenic and Natural Noise Sources

    DTIC Science & Technology

    2013-09-30

    e.g., critical ratios ) are often used to describe and predict auditory masking. For this task, detection thresholds for a 10 kHz tone were measured in...unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 2 determine the relationship between noise metrics and masked tonal ...the residual errors (FIG 3) demonstrates that the two-parameter model produces much better fits than critical ratio predictions, while still being

  16. Multiresolution scanning imager with spatially uniform noise response based on a new class of Hadamard masks

    NASA Astrophysics Data System (ADS)

    Bone, Donald J.; Popescu, Dan C.

    2000-05-01

    In spite the prodigious growth in the market for digital cameras, they have yet to displace film-based cameras in the consumer market. This is largely due to the high cost of photographic resolution sensors. One possible approach to producing a low cost, high resolution sensor is to linearly scan a masked low resolution sensor. Masking of the sensor elements allows transform domain imaging. Multiple displaced exposures of such a masked sensor permits the device to acquire a linear transform of a higher resolution representation of the image than that defined by the sensor element dimensions. Various approaches have been developed in the past along these lines, but they often suffer from poor sensitivity, difficulty in being adapted to a 2D sensor or spatially variable noise response. This paper presents an approach based on a new class of Hadamard masks--Uniform Noise Hadamard Masks--which has superior sensitivity to simple sampling approaches and retains the multiresolution capabilities of certain Hadamard matrices, while overcoming the non-uniform noise response problems of some simple Hadamard based masks.

  17. Effects of Masking Noise on Laryngeal Resistance for Breathy, Normal, and Pressed Voice

    ERIC Educational Resources Information Center

    Grillo, Elizabeth U.; Abbott, Katherine Verdolini; Lee, Timothy D.

    2010-01-01

    Purpose: The purpose of the present study was to explore the effects of masking noise on laryngeal resistance for breathy, normal, and pressed voice in vocally trained women. Method: Eighteen vocally trained women produced breathy, normal, and pressed voice across 7 fundamental frequencies during a repeated CV utterance of /pi/ under normal and…

  18. Feedforward and Feedback Control in Apraxia of Speech: Effects of Noise Masking on Vowel Production

    ERIC Educational Resources Information Center

    Maas, Edwin; Mailend, Marja-Liisa; Guenther, Frank H.

    2015-01-01

    Purpose: This study was designed to test two hypotheses about apraxia of speech (AOS) derived from the Directions Into Velocities of Articulators (DIVA) model (Guenther et al., 2006): the feedforward system deficit hypothesis and the feedback system deficit hypothesis. Method: The authors used noise masking to minimize auditory feedback during…

  19. Perceptual Classification Images from Vernier Acuity Masked by Noise

    NASA Technical Reports Server (NTRS)

    Ahumada, A. J.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    Letting external noise rather than internal noise limit discrimination performance allows information to be extracted about the observer's stimulus classification rule. A perceptual classification image is the correlation over trials between the noise amplitude at a spatial location and the observer's responses. If, for example, the observer followed the rule of the ideal observer, the perceptual classification image would be an estimate of the ideal observer filter, the difference between the two unmasked images being discriminated. Perceptual classification images were estimated for a vernier discrimination task. The display screen had 48 pixels per degree horizontally and vertically. The no-offset image had a dark horizontal line of 4 pixels, a 1 pixel space, and 4 more dark pixels. Classification images were based on 1600 discrimination trials with the line contrast adjusted to keep the error rate near 25 percent. In the offset image, the second line was one pixel higher. Unlike the ideal observer filter (a horizontal dipole), the observer perceptual classification images are strongly oriented. Fourier transforms of the classification images had a peak amplitude near one cycle per degree and an orientation near 25 degrees. The spatial spread is much more than image blur predicts, and probably indicates the spatial position uncertainty in the task.

  20. Simultaneous suppression of noise and reverberation in cochlear implants using a ratio masking strategy.

    PubMed

    Hazrati, Oldooz; Sadjadi, Seyed Omid; Loizou, Philipos C; Hansen, John H L

    2013-11-01

    Cochlear implant (CI) recipients' ability to identify words is reduced in noisy or reverberant environments. The speech identification task for CI users becomes even more challenging in conditions where both reverberation and noise co-exist as they mask the spectro-temporal cues of speech in a rather complementary fashion. Ideal channel selection (ICS) was found to result in significantly more intelligible speech when applied to the noisy, reverberant, as well as noisy reverberant speech. In this study, a blind single-channel ratio masking strategy is presented to simultaneously suppress the negative effects of reverberation and noise on speech identification performance for CI users. In this strategy, noise power spectrum is estimated from the non-speech segments of the utterance while reverberation spectral variance is computed as a delayed and scaled version of the reverberant speech spectrum. Based on the estimated noise and reverberation power spectra, a weight between 0 and 1 is assigned to each time-frequency unit to form the final mask. Listening experiments conducted with CI users in two reverberant conditions (T60 = 0.6 and 0.8 s) at a signal-to-noise ratio of 15 dB indicate substantial improvements in speech intelligibility in both reverberant-alone and noisy reverberant conditions considered.

  1. Acoustic vector sensor beamforming reduces masking from underwater industrial noise during passive monitoring.

    PubMed

    Thode, Aaron M; Kim, Katherine H; Norman, Robert G; Blackwell, Susanna B; Greene, Charles R

    2016-04-01

    Masking from industrial noise can hamper the ability to detect marine mammal sounds near industrial operations, whenever conventional (pressure sensor) hydrophones are used for passive acoustic monitoring. Using data collected from an autonomous recorder with directional capabilities (Directional Autonomous Seafloor Acoustic Recorder), deployed 4.1 km from an arctic drilling site in 2012, the authors demonstrate how conventional beamforming on an acoustic vector sensor can be used to suppress noise arriving from a narrow sector of geographic azimuths. Improvements in signal-to-noise ratio of up to 15 dB are demonstrated on bowhead whale calls, which were otherwise undetectable using conventional hydrophones.

  2. Initial clinical experience of an ultrasonic strain imaging system with novel noise-masking capability.

    PubMed

    Chen, L; Freeman, S J; Gee, A H; Housden, R J; Prager, R W; Sinnatamby, R; Treece, G M

    2010-08-01

    Quasistatic strain imaging is a form of elastography that can produce qualitative images of tissue stiffness with only software modifications to conventional ultrasound hardware. Unlike current commercial offerings, the novel strain-imaging system that is the subject of this paper displays regions of signal decorrelation using an overlaid colour mask and can also produce three-dimensional (3D) strain images. In illustrative studies of the breast, testis and thyroid, the colour mask is seen to reduce the potential to misinterpret noise as meaningful stiffness information, and also helps to differentiate cystic and solid lesions. High-quality imaging of the testis in vivo demonstrates that 3D strain imaging is feasible.

  3. Simulated masking of right whale sounds by shipping noise: incorporating a model of the auditory periphery.

    PubMed

    Cunningham, Kane A; Mountain, David C

    2014-03-01

    Many species of large, mysticete whales are known to produce low-frequency communication sounds. These low-frequency sounds are susceptible to communication masking by shipping noise, which also tends to be low frequency in nature. The size of these species makes behavioral assessment of auditory capabilities in controlled, captive environments nearly impossible, and field-based playback experiments are expensive and necessarily limited in scope. Hence, it is desirable to produce a masking model for these species that can aid in determining the potential effects of shipping and other anthropogenic noises on these protected animals. The aim of this study was to build a model that combines a sophisticated representation of the auditory periphery with a spectrogram-based decision stage to predict masking levels. The output of this model can then be combined with a habitat-appropriate propagation model to calculate the potential effects of noise on communication range. For this study, the model was tested on three common North Atlantic right whale communication sounds, both to demonstrate the method and to probe how shipping noise affects the detection of sounds with varying spectral and temporal characteristics.

  4. JAPE 91: Influence of terrain masking of the acoustic propagation of helicopter noise

    NASA Technical Reports Server (NTRS)

    Naz, P.

    1993-01-01

    The acoustic propagation in the case of a noise source masked by a small element of terrain has been investigated experimentally. These data have been measured during the 'terrain masking' experiment of the NATO JAPE 91 experimental campaign. The main objective of that experiment was to study the acoustic detection of a helicopter masked by a small hill. Microphones have been placed at different locations on the shadow zone of the hill to study the effect of the terrain obstruction on sound propagation. The results presented come from data measured by Atlas Elektronik and by ISL, and have been processed together. The terrain obstruction causes an excess attenuation of the SPL (Sound Pressure Level) for all the frequencies, but this attenuation is more effective for the high frequencies than for the low frequencies. Results typical of diffraction phenomena have been observed; the SPL is minimal at the foot of the hill and is relatively constant beyond it.

  5. Maintaining acoustic communication at a cocktail party: heterospecific masking noise improves signal detection through frequency separation

    PubMed Central

    Siegert, M. E.; Römer, H.; Hartbauer, M.

    2014-01-01

    SUMMARY We examined acoustic masking in a chirping katydid species of the Mecopoda elongata complex due to interference with a sympatric Mecopoda species where males produce continuous trills at high amplitudes. Frequency spectra of both calling songs range from 1 to 80 kHz; the chirper species has more energy in a narrow frequency band at 2 kHz and above 40 kHz. Behaviourally, chirper males successfully phase-locked their chirps to playbacks of conspecific chirps under masking conditions at signal-to-noise ratios (SNRs) of −8 dB. After the 2 kHz band in the chirp had been equalised to the level in the masking trill, the breakdown of phase-locked synchrony occurred at a SNR of +7 dB. The remarkable receiver performance is partially mirrored in the selective response of a first-order auditory interneuron (TN1) to conspecific chirps under these masking conditions. However, the selective response is only maintained for a stimulus including the 2 kHz component, although this frequency band has no influence on the unmasked TN1 response. Remarkably, the addition of masking noise at 65 dB sound pressure level (SPL) to threshold response levels of TN1 for pure tones of 2 kHz enhanced the sensitivity of the response by 10 dB. Thus, the spectral dissimilarity between masker and signal at a rather low frequency appears to be of crucial importance for the ability of the chirping species to communicate under strong masking by the trilling species. We discuss the possible properties underlying the cellular/synaptic mechanisms of the ‘novelty detector’. PMID:24307713

  6. The role of binary mask patterns in automatic speech recognition in background noise.

    PubMed

    Narayanan, Arun; Wang, DeLiang

    2013-05-01

    Processing noisy signals using the ideal binary mask improves automatic speech recognition (ASR) performance. This paper presents the first study that investigates the role of binary mask patterns in ASR under various noises, signal-to-noise ratios (SNRs), and vocabulary sizes. Binary masks are computed either by comparing the SNR within a time-frequency unit of a mixture signal with a local criterion (LC), or by comparing the local target energy with the long-term average spectral energy of speech. ASR results show that (1) akin to human speech recognition, binary masking significantly improves ASR performance even when the SNR is as low as -60 dB; (2) the ASR performance profiles are qualitatively similar to those obtained in human intelligibility experiments; (3) the difference between the LC and mixture SNR is more correlated to the recognition accuracy than LC; (4) LC at which the performance peaks is lower than 0 dB, which is the threshold that maximizes the SNR gain of processed signals. This broad agreement with human performance is rather surprising. The results also indicate that maximizing the SNR gain is probably not an appropriate goal for improving either human or machine recognition of noisy speech.

  7. How cigarette additives are used to mask environmental tobacco smoke

    PubMed Central

    Connolly, G.; Wayne, G.; Lymperis, D.; Doherty, M.

    2000-01-01

    OBJECTIVE—To understand the tobacco industry's research on and use of cigarette additives that alter the perception of exposure to environmental tobacco smoke (ETS).
DATA SOURCES—Internal documents from four websites maintained by the major US tobacco manufacturers and company patents pertaining to the use of ETS altering additives obtained from the US Patent and Trademark Office online database.
STUDY SELECTION—Electronic searches of the four industry websites and the US patent database were conducted using keywords to identify relevant data.
DATA EXTRACTION—Industry documents and patents obtained using an exploratory snowball sampling method were reviewed and grouped into four general categories according to whether the additive(s) described affected ETS visibility, odour, irritation, or emissions. Accuracy of isolated findings was validated through cross comparison of the data sources.
DATA SYNTHESIS—Results of this preliminary study provide evidence that tobacco manufacturers have conducted extensive research on the use of chemical additives to reduce, mask, or otherwise alter the visibility, odour, irritation, or emission of ETS.
CONCLUSIONS—Findings suggest that the tobacco industry uses additives to reduce the perception of ETS. To protect the public, appropriate regulation of tobacco additives should be mandated.


Keywords: environmental tobacco smoke; tobacco industry; additives; masking PMID:10982572

  8. Charting environmental pollution. [by noise measurements

    NASA Technical Reports Server (NTRS)

    Halpert, E.; Bizo, F.; Karacsonyi, Z.

    1974-01-01

    It is found that areas affected by different noxious agents are within the limits traced for high noise level areas; consequently, it is suggested that high noise pressure levels should be used as the primary indication of environmental pollution. A complex methodology is reported for charting environmental pollution due to physical, chemical and biological noxious agents on the scale of an industrial district.

  9. Hearing Sensitivity to Shifts of Rippled-Spectrum Sound Signals in Masking Noise.

    PubMed

    Nechaev, Dmitry I; Milekhina, Olga N; Supin, Alexander Ya

    2015-01-01

    The goal of the study was to enlarge knowledge of discrimination of complex sound signals by the auditory system in masking noise. For that, influence of masking noise on detection of shift of rippled spectrum was studied in normal listeners. The signal was a shift of ripple phase within a 0.5-oct wide rippled spectrum centered at 2 kHz. The ripples were frequency-proportional (throughout the band, ripple spacing was a constant proportion of the ripple center frequency). Simultaneous masker was a 0.5-oct noise below-, on-, or above the signal band. Both the low-frequency (center frequency 1 kHz) and on-frequency (the same center frequency as for the signal) maskers increased the thresholds for detecting ripple phase shift. However, the threshold dependence on the masker level was different for these two maskers. For the on-frequency masker, the masking effect primarily depended on the masker/signal ratio: the threshold steeply increased at a ratio of 5 dB, and no shift was detectable at a ratio of 10 dB. For the low-frequency masker, the masking effect primarily depended on the masker level: the threshold increased at a masker level of 80 dB SPL, and no shift was detectable at a masker level of 90 dB (for a signal level of 50 dB) or 100 dB (for a signal level of 80 dB). The high-frequency masker had little effect. The data were successfully simulated using an excitation-pattern model. In this model, the effect of the on-frequency masker appeared to be primarily due to a decrease of ripple depth. The effect of the low-frequency masker appeared due to widening of the auditory filters at high sound levels.

  10. Hearing Sensitivity to Shifts of Rippled-Spectrum Sound Signals in Masking Noise

    PubMed Central

    Nechaev, Dmitry I.; Milekhina, Olga N.; Supin, Alexander Ya.

    2015-01-01

    The goal of the study was to enlarge knowledge of discrimination of complex sound signals by the auditory system in masking noise. For that, influence of masking noise on detection of shift of rippled spectrum was studied in normal listeners. The signal was a shift of ripple phase within a 0.5-oct wide rippled spectrum centered at 2 kHz. The ripples were frequency-proportional (throughout the band, ripple spacing was a constant proportion of the ripple center frequency). Simultaneous masker was a 0.5-oct noise below-, on-, or above the signal band. Both the low-frequency (center frequency 1 kHz) and on-frequency (the same center frequency as for the signal) maskers increased the thresholds for detecting ripple phase shift. However, the threshold dependence on the masker level was different for these two maskers. For the on-frequency masker, the masking effect primarily depended on the masker/signal ratio: the threshold steeply increased at a ratio of 5 dB, and no shift was detectable at a ratio of 10 dB. For the low-frequency masker, the masking effect primarily depended on the masker level: the threshold increased at a masker level of 80 dB SPL, and no shift was detectable at a masker level of 90 dB (for a signal level of 50 dB) or 100 dB (for a signal level of 80 dB). The high-frequency masker had little effect. The data were successfully simulated using an excitation-pattern model. In this model, the effect of the on-frequency masker appeared to be primarily due to a decrease of ripple depth. The effect of the low-frequency masker appeared due to widening of the auditory filters at high sound levels. PMID:26462066

  11. Word recognition in noise at higher-than-normal levels: Decreases in scores and increases in masking

    NASA Astrophysics Data System (ADS)

    Dubno, Judy R.; Horwitz, Amy R.; Ahlstrom, Jayne B.

    2005-08-01

    Under certain conditions, speech recognition in noise decreases above conversational levels when signal-to-noise ratio is held constant. The current study was undertaken to determine if nonlinear growth of masking and the subsequent reduction in ``effective'' signal-to-noise ratio accounts for this decline. Nine young adults with normal hearing listened to monosyllabic words at three levels in each of three levels of a masker shaped to match the speech spectrum. An additional low-level noise equated audibility by producing equivalent masked thresholds for all subjects. If word recognition was determined entirely by signal-to-noise ratio and was independent of overall speech and masker levels, scores at a given signal-to-noise ratio should remain constant with increasing level. Masked pure-tone thresholds measured in the speech-shaped maskers increased linearly with increasing masker level at lower frequencies but nonlinearly at higher frequencies, consistent with nonlinear growth of upward spread of masking that followed the peaks in the spectrum of the speech-shaped masker. Word recognition declined significantly with increasing level when signal-to-noise ratio was held constant which was attributed to nonlinear growth of masking and reduced ``effective'' signal-to-noise ratio at high speech-shaped masker levels, as indicated by audibility estimates based on the Articulation Index.

  12. Relationship between masking release in fluctuating maskers and speech reception thresholds in stationary noise.

    PubMed

    Christiansen, Claus; Dau, Torsten

    2012-09-01

    In contrast to normal-hearing (NH) listeners, hearing-impaired (HI) listeners often show strongly reduced masking release (MR) in fluctuating interferers, which has commonly been associated with spectral and temporal processing deficits. However, it has recently been proposed that the reduced MR could result from an increased speech recognition threshold (SRT) in stationary noise [Bernstein and Grant, J. Acoust. Soc. Am. 125, 3358-3372 (2009)]. This was tested by presenting noise-band vocoded as well as low-pass and high-pass filtered stimuli to NH listeners, thereby increasing their stationary-noise SRTs to those of the HI listeners. If the primary determinant of MR is the SRT in stationary noise then the amount of the MR should be independent of the type of processing used to obtain the stationary-noise SRT. However, the relation between the amount of MR and the stationary-noise SRT depended on the type of processing. For a fluctuating interferer, none of the processing conditions reduced the MR of the NH listeners to that of the HI listeners. In contrast, for an interfering talker, the results for vocoded stimuli were similar to those of the HI listeners. Overall, these results suggest that the observed MR is only partially related to the stationary-noise SRT.

  13. Cardiovascular effects of environmental noise exposure

    PubMed Central

    Münzel, Thomas; Gori, Tommaso; Babisch, Wolfgang; Basner, Mathias

    2014-01-01

    The role of noise as an environmental pollutant and its impact on health are being increasingly recognized. Beyond its effects on the auditory system, noise causes annoyance and disturbs sleep, and it impairs cognitive performance. Furthermore, evidence from epidemiologic studies demonstrates that environmental noise is associated with an increased incidence of arterial hypertension, myocardial infarction, and stroke. Both observational and experimental studies indicate that in particular night-time noise can cause disruptions of sleep structure, vegetative arousals (e.g. increases of blood pressure and heart rate) and increases in stress hormone levels and oxidative stress, which in turn may result in endothelial dysfunction and arterial hypertension. This review focuses on the cardiovascular consequences of environmental noise exposure and stresses the importance of noise mitigation strategies for public health. PMID:24616334

  14. Selective attention and the auditory vertex potential. 2: Effects of signal intensity and masking noise

    NASA Technical Reports Server (NTRS)

    Schwent, V. L.; Hillyard, S. A.; Galambos, R.

    1975-01-01

    A randomized sequence of tone bursts was delivered to subjects at short inter-stimulus intervals with the tones originating from one of three spatially and frequency specific channels. The subject's task was to count the tones in one of the three channels at a time, ignoring the other two, and press a button after each tenth tone. In different conditions, tones were given at high and low intensities and with or without a background white noise to mask the tones. The N sub 1 component of the auditory vertex potential was found to be larger in response to attended channel tones in relation to unattended tones. This selective enhancement of N sub 1 was minimal for loud tones presented without noise and increased markedly for the lower tone intensity and in noise added conditions.

  15. Mapping Urban Environmental Noise Using Smartphones

    PubMed Central

    Zuo, Jinbo; Xia, Hao; Liu, Shuo; Qiao, Yanyou

    2016-01-01

    Noise mapping is an effective method of visualizing and accessing noise pollution. In this paper, a noise-mapping method based on smartphones to effectively and easily measure environmental noise is proposed. By using this method, a noise map of an entire area can be created using limited measurement data. To achieve the measurement with certain precision, a set of methods was designed to calibrate the smartphones. Measuring noise with mobile phones is different from the traditional static observations. The users may be moving at any time. Therefore, a method of attaching an additional microphone with a windscreen is proposed to reduce the wind effect. However, covering an entire area is impossible. Therefore, an interpolation method is needed to achieve full coverage of the area. To reduce the influence of spatial heterogeneity and improve the precision of noise mapping, a region-based noise-mapping method is proposed in this paper, which is based on the distribution of noise in different region types tagged by volunteers, to interpolate and combine them to create a noise map. To validate the effect of the method, a comparison of the interpolation results was made to analyse our method and the ordinary Kriging method. The result shows that our method is more accurate in reflecting the local distribution of noise and has better interpolation precision. We believe that the proposed noise-mapping method is a feasible and low-cost noise-mapping solution. PMID:27754359

  16. [Stapedial reflex under auditory masking of bone canal: 1- The effect of white noise on threshold values].

    PubMed

    Cassano, P; Mininni, F; Paulillo, A

    1983-11-30

    The authors have studied the behaviour of the A.R. threshold under bone way masking sent to the vertex. The masking caused changings of the recorded track; a change of the compliance was observed in the 60% of the subjects and a rythmic waving of the (isoelectric) line was observed in 40% of the subjects. Upon these changes the A.R. were recorded for the tone test sent at similar values (almost equal) at those recorded without any kind of masker, even if a threshold shift sometimes big, existed because of the high intensity of the masking noise. The authors are making further researches to explain the meaning of these changes.

  17. Attenuated phase-shift mask for mitigation of photon shot noise effect in contact hole pattern for extreme ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Kim, Jung Sik; Hong, Seongchul; Lee, Jae Uk; Lee, Seung Min; Ahn, Jinho

    2014-09-01

    In extreme ultraviolet lithography (EUVL), insufficient light source power is the biggest concern for high-volume manufacturing. Additionally, the photon shot noise (PSN) effect is believed to be the main source of degradation in various aspects of imaging performance. In this study, we propose an attenuated phase-shift mask (PSM) as a solution to both of these issues, yielding improved mask performance for the printing of small contact hole (C/H) patterns. Our PSM shows superior imaging performance over that of a binary intensity mask. We speculate that the stochastic imaging characteristics are improved by the enhanced diffraction efficiency of the PSM.

  18. Practical ranges of loudness levels of various types of environmental noise, including traffic noise, aircraft noise, and industrial noise.

    PubMed

    Salomons, Erik M; Janssen, Sabine A

    2011-06-01

    In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a noise signal varies considerably with the shape of the frequency spectrum of the noise signal. In particular the bandwidth of the spectrum has a large effect on the loudness level, due to the effect of critical bands in the human hearing system. The low-frequency content of the spectrum also has an effect on the loudness level. In this note the relation between loudness level and A-weighted sound level is analyzed for various environmental noise spectra, including spectra of traffic noise, aircraft noise, and industrial noise. From loudness levels calculated for these environmental noise spectra, diagrams are constructed that show the relation between loudness level, A-weighted sound level, and shape of the spectrum. The diagrams show that the upper limits of the loudness level for broadband environmental noise spectra are about 20 to 40 phon higher than the lower limits for narrowband spectra, which correspond to the loudness levels of pure tones. The diagrams are useful for assessing limitations and potential improvements of environmental noise control methods and policy based on A-weighted sound levels.

  19. Practical Ranges of Loudness Levels of Various Types of Environmental Noise, Including Traffic Noise, Aircraft Noise, and Industrial Noise

    PubMed Central

    Salomons, Erik M.; Janssen, Sabine A.

    2011-01-01

    In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a noise signal varies considerably with the shape of the frequency spectrum of the noise signal. In particular the bandwidth of the spectrum has a large effect on the loudness level, due to the effect of critical bands in the human hearing system. The low-frequency content of the spectrum also has an effect on the loudness level. In this note the relation between loudness level and A-weighted sound level is analyzed for various environmental noise spectra, including spectra of traffic noise, aircraft noise, and industrial noise. From loudness levels calculated for these environmental noise spectra, diagrams are constructed that show the relation between loudness level, A-weighted sound level, and shape of the spectrum. The diagrams show that the upper limits of the loudness level for broadband environmental noise spectra are about 20 to 40 phon higher than the lower limits for narrowband spectra, which correspond to the loudness levels of pure tones. The diagrams are useful for assessing limitations and potential improvements of environmental noise control methods and policy based on A-weighted sound levels. PMID:21776205

  20. Color and luminance spatial tuning estimated by noise masking in the absence of off-frequency looking

    NASA Astrophysics Data System (ADS)

    Angeles Losada, M.; Mullen, Kathy T.

    1995-02-01

    We assessed the contribution of off-frequency looking for pattern detection and obtained bandwidths for chromatic and luminance mechanisms in conditions free from this effect. We used a simultaneous spatial masking technique with Gaussian enveloped sinusoidal test stimuli (0.5 cycle / deg) and filtered one-dimensional static-noise masks whose spectral power was uniformly distributed per octave. Stimuli were modulated in the chromatic (isoluminant red-green) or the luminance (yellow-black) domain. Color and luminance detection thresholds were compared for low-pass, high-pass, and notch- (band-stopped) filtered noise. We obtained the densities, masking by notched noise is greater than the summed masking of the high- and low-pass noise, indicating the presence of off-frequency looking for both color and luminance detection. There is no evidence for off-frequency looking at lower power densities. (2) Using notch-filtered noise, which avoids the problem of off-frequency looking, we found that color processing is subserved by bandpass channels with bandwidths similar to those revealed for luminance processing. (3) Both color and luminance mechanisms appear to have bandwidths proportional to their center frequency (constant in octaves). (4) The lower and upper sides of the color and luminance tuning functions were estimated individually by use of high-pass and low-pass noise of a low power density and are revealed to

  1. Noise reduction for curve-linear structures in real time fluoroscopy applications using directional binary masks

    PubMed Central

    Wagner, Martin; Yang, Pengfei; Schafer, Sebastian; Strother, Charles; Mistretta, Charles

    2015-01-01

    Purpose: Recent efforts in the reconstruction of interventional devices from two distinct views require the segmentation of the object in both fluoroscopic images. Noise might decrease the quality of the segmentation and cause artifacts in the reconstruction. The noise level depends on the x-ray dose the patient is exposed to. The proposed algorithm reduces the noise and enhances the separability of curvilinear devices in background subtracted fluoroscopic images to allow a more accurate segmentation. Methods: The algorithm uses a set of binary masks to estimate a line conformity measure that determines the best direction for a directional filter kernel. If the calculated value exceeds a certain threshold, the directional kernel is used to obtain the filtered value. Otherwise, an isotropic filter kernel is used. Results: The evaluation was performed on a set of 36 fluoroscopic images using a vascular head phantom with three different guidewires and nine different x-ray dosages from 6 nGy/pulse to 45 nGy/pulse as well as a clinical data set containing ten images. Compared with wavelet shrinkage and the bilateral filter, the proposed algorithm increased the average contrast to noise ratio by at least 17.8% for the phantom and 68.9% for the clinical images. The accuracy of the device segmentation was improved on average by at least 17.3% and 14.0%, respectively. Conclusions: The proposed algorithm was able to significantly reduce the amount of noise in the images and therefore increase the quality of the device segmentations compared to both the bilateral filter and the wavelet thresholding approach for all acquired noise levels using rotating directional filter kernels near line structures and isotropic kernels for the background. The application of the proposed algorithm for the 3D reconstruction of curvilinear devices from two views would allow a more accurate reconstruction of the device. PMID:26233192

  2. A cocktail party model of spatial release from masking by both noise and speech interferers.

    PubMed

    Jones, Gary L; Litovsky, Ruth Y

    2011-09-01

    A mathematical formula for estimating spatial release from masking (SRM) in a cocktail party environment would be useful as a simpler alternative to computationally intensive algorithms and may enhance understanding of underlying mechanisms. The experiment presented herein was designed to provide a strong test of a model that divides SRM into contributions of asymmetry and angular separation [Bronkhorst (2000). Acustica 86, 117-128] and to examine whether that model can be extended to include speech maskers. Across masker types the contribution to SRM of angular separation of maskers from the target was found to grow at a diminishing rate as angular separation increased within the frontal hemifield, contrary to predictions of the model. Speech maskers differed from noise maskers in the overall magnitude of SRM and in the contribution of angular separation (both greater for speech). These results were used to develop a modified model that achieved good fits to data for noise maskers (ρ=0.93) and for speech maskers (ρ=0.94) while using the same functions to describe separation and asymmetry components of SRM for both masker types. These findings suggest that this approach can be used to accurately model SRM for speech maskers in addition to primarily "energetic" noise maskers.

  3. A cocktail party model of spatial release from masking by both noise and speech interferers a)

    PubMed Central

    Jones, Gary L.; Litovsky, Ruth Y.

    2011-01-01

    A mathematical formula for estimating spatial release from masking (SRM) in a cocktail party environment would be useful as a simpler alternative to computationally intensive algorithms and may enhance understanding of underlying mechanisms. The experiment presented herein was designed to provide a strong test of a model that divides SRM into contributions of asymmetry and angular separation [Bronkhorst (2000). Acustica 86, 117–128] and to examine whether that model can be extended to include speech maskers. Across masker types the contribution to SRM of angular separation of maskers from the target was found to grow at a diminishing rate as angular separation increased within the frontal hemifield, contrary to predictions of the model. Speech maskers differed from noise maskers in the overall magnitude of SRM and in the contribution of angular separation (both greater for speech). These results were used to develop a modified model that achieved good fits to data for noise maskers (ρ = 0.93) and for speech maskers (ρ = 0.94) while using the same functions to describe separation and asymmetry components of SRM for both masker types. These findings suggest that this approach can be used to accurately model SRM for speech maskers in addition to primarily “energetic” noise maskers. PMID:21895087

  4. Phase effects in masking by harmonic complexes: detection of bands of speech-shaped noise.

    PubMed

    Deroche, Mickael L D; Culling, John F; Chatterjee, Monita

    2014-11-01

    When phase relationships between partials of a complex masker produce highly modulated temporal envelopes on the basilar membrane, listeners may detect speech information from temporal dips in the within-channel masker envelopes. This source of masking release (MR) is however located in regions of unresolved masker partials and it is unclear how much of the speech information in these regions is really needed for intelligibility. Also, other sources of MR such as glimpsing in between resolved masker partials may provide sufficient information from regions that disregard phase relationships. This study simplified the problem of speech recognition to a masked detection task. Target bands of speech-shaped noise were restricted to frequency regions containing either only resolved or only unresolved masker partials, as a function of masker phase relationships (sine or random), masker fundamental frequency (F0) (50, 100, or 200 Hz), and masker spectral profile (flat-spectrum or speech-shaped). Although masker phase effects could be observed in unresolved regions at F0s of 50 and 100 Hz, it was only at 50-Hz F0 that detection thresholds were ever lower in unresolved than in resolved regions, suggesting little role of envelope modulations for harmonic complexes with F0s in the human voice range and at moderate level.

  5. Effects of white noise masking and low pass filtering on speech kinematics.

    PubMed

    Forrest, K; Abbas, P J; Zimmermann, G N

    1986-12-01

    The effects of reduced auditory information on spatial and temporal parameters of speech production were investigated using cinefluorographic techniques. While subjects read a series of test words embedded in carrier sentences, they received normal auditory information, auditory information regarding only the first formant of their production, or high level noise to mask all formant information. Kinematic analyses indicated that while there were some changes across conditions, these changes were not consistent either within or across the subjects. Parameters that were affected included mean displacement, vocal tract shape, interarticulator timing, and steady state duration. The results suggest that auditory information plays a role in maintaining dynamic aspects of speech kinematics. That is, while speech can be produced without auditory information, the precise action and coordination that characteristic normal production may be altered.

  6. Speech intelligibility in reverberation with ideal binary masking: effects of early reflections and signal-to-noise ratio threshold.

    PubMed

    Roman, Nicoleta; Woodruff, John

    2013-03-01

    Ideal binary masking is a signal processing technique that separates a desired signal from a mixture by retaining only the time-frequency units where the signal-to-noise ratio (SNR) exceeds a predetermined threshold. In reverberant conditions there are multiple possible definitions of the ideal binary mask in that one may choose to treat the target early reflections as either desired signal or noise. The ideal binary mask may therefore be parameterized by the reflection boundary, a predetermined division point between early and late reflections. Another important parameter is the local SNR threshold used in labeling the time-frequency units as either target or background. Two experiments were designed to assess the impact of these two parameters on speech intelligibility with ideal binary masking for normal-hearing listeners in reverberant conditions. Experiment 1 shows that in order to achieve intelligibility improvements only the early reflections should be preserved by the binary mask. Moreover, it shows that the effective SNR should be accounted for when deciding the local threshold optimal range. Experiment 2 shows that with long reverberation times, intelligibility improvements are only obtained when the reflection boundary is 100 ms or less. Also, the experiment suggests that binary masking can be used for dereverberation.

  7. Cold Regions Environmental Test of CB Protective Masks.

    DTIC Science & Technology

    1986-11-01

    Question 23: a. When you put your mask on and cleared it, did the mask lenses become foggy? (Note: fog means moisture on the inside or outside of the...have any frost form on the lenses ? (note: frost means moisture /ice.) Yes No b. If yes, what was the problem and under what circumstances did you...cold-wet uniform is designed to afford maximum protection against the hazards of changing temperatures, rain, wet snow, mud, and slush of a cold-wet

  8. Modeling the anti-masking effects of the olivocochlear reflex in auditory nerve responses to tones in sustained noise.

    PubMed

    Chintanpalli, Ananthakrishna; Jennings, Skyler G; Heinz, Michael G; Strickland, Elizabeth A

    2012-04-01

    The medial olivocochlear reflex (MOCR) has been hypothesized to provide benefit for listening in noise. Strong physiological support for an anti-masking role for the MOCR has come from the observation that auditory nerve (AN) fibers exhibit reduced firing to sustained noise and increased sensitivity to tones when the MOCR is elicited. The present study extended a well-established computational model for normal-hearing and hearing-impaired AN responses to demonstrate that these anti-masking effects can be accounted for by reducing outer hair cell (OHC) gain, which is a primary effect of the MOCR. Tone responses in noise were examined systematically as a function of tone level, noise level, and OHC gain. Signal detection theory was used to predict detection and discrimination for different spontaneous rate fiber groups. Decreasing OHC gain decreased the sustained noise response and increased maximum discharge rate to the tone, thus modeling the ability of the MOCR to decompress AN fiber rate-level functions. Comparing the present modeling results with previous data from AN fibers in decerebrate cats suggests that the ipsilateral masking noise used in the physiological study may have elicited up to 20 dB of OHC gain reduction in addition to that inferred from the contralateral noise effects. Reducing OHC gain in the model also extended the dynamic range for discrimination over a wide range of background noise levels. For each masker level, an optimal OHC gain reduction was predicted (i.e., where maximum discrimination was achieved without increased detection threshold). These optimal gain reductions increased with masker level and were physiologically realistic. Thus, reducing OHC gain can improve tone-in-noise discrimination even though it may produce a “hearing loss” in quiet. Combining MOCR effects with the sensorineural hearing loss effects already captured by this computational AN model will be beneficial for exploring the implications of their interaction

  9. The effect of masking noise on acoustic-phonetic contrasts in post-lingually deafened cochlear implant users

    NASA Astrophysics Data System (ADS)

    Vick, Jennell C.; Perkell, Joseph S.; Stockmann, Ellen; Zandipour, Majid; Lane, Harlan; Tiede, Mark

    2003-10-01

    This study examined the effect on the vowel contrast distance (average inter-vowel distance in the F1-F2 plane) of gradually decreasing the signal-to-noise ratio (SNR) in the auditory feedback of a post-lingually deafened cochlear implant (CI) user at 1-month and 1-year following CI processor activation. Masking noise, mixed with normal levels of speech feedback, was presented through the headpiece of a research sound processor to the CI user. As a control, an analogous procedure was used for a normal-hearing speaker where the masking noise and speech feedback were delivered over headphones. The SNR was gradually decreased over seven steps as the speakers produced ten repetitions of two vowel contrasts (æ\\/[g\\/] and i\\/u). Speech SPL and vowel contrast distance were measured at all seven masking noise levels. Data from both subjects showed that SPL gradually increased with decreased SNR, while contrast distance decreased. The effect was greater after 1 year of experience with a CI than at 1 month. The effect in the NH speaker was similar to that noted in the CI user after 1 year of experience. Data from additional subjects will be analyzed and reported. [Work supported by NIH Grant No. R01 DC03007.

  10. Environmental issues: noise, rail noise, and high-speed rail

    SciTech Connect

    Hall, F.L.; Welland, J.D.; Bragdon, C.R.; Houtman, J.W.; Immers, B.H.

    1987-01-01

    The six papers in the report deal with the following areas: the effect of noise barriers on the market value of adjacent residential properties; control of airport- and aircraft-related noise in the United States; a traffic-assignment model to reduce noise annoyance in urban networks; a survey of railroad occupational noise sources; a prediction procedure for rail transportation ground-borne noise and vibration; and high-speed rail in California: the dream, the process, and the reality.

  11. The Masking Effect Of Fluoroscopic X-Ray Noise As A Function Of Unsharpness And Intensity And The Viewing Distance

    NASA Astrophysics Data System (ADS)

    Hoen, P. J.'t.

    1982-11-01

    The masking effect is expressed in terms of the visual threshold contrast of bars and disks, A very sensitive and fast psychometric method is developed for the measurement of the threshold contrast. Substantial variations of the unsharpness have relatively small influence. This may well be predicted by the noise equivalent aperture concept provided that a visual system unsharpness is also taken into account. This unsharpness may correspond to the newly developed1. visual system modulation transfer function which gives good predictions for the influence of the unsharpness of the object on the visibility. The threshold appears to be inversely proportional to the square root of the X-ray exposure rate, as is predicted by models based on the statistical variation of the noise. As apparently the perceived unsharpness is not very important, the masking effect is correctly predicted to be inversely proportional to the viewing distance.

  12. Age-related differences in weighting and masking of two cues to word-final stop voicing in noise

    NASA Astrophysics Data System (ADS)

    Nittrouer, Susan

    2005-08-01

    Because laboratory studies are conducted in optimal listening conditions, often with highly stylized stimuli that attenuate or eliminate some naturally occurring cues, results may have constrained applicability to the ``real world.'' Such studies show that English-speaking adults weight vocalic duration greatly and formant offsets slightly in voicing decisions for word-final obstruents. Using more natural stimuli, Nittrouer [J. Acoust. Soc. Am. 115, 1777-1790 (2004)] found different results, raising questions about what would happen if experimental conditions were even more like the real world. In this study noise was used to simulate the real world. Edited natural words with voiced and voiceless final stops were presented in quiet and noise to adults and children (4 to 8 years) for labeling. Hypotheses tested were (1) Adults (and perhaps older children) would weight vocalic duration more in noise than in quiet; (2) Previously reported age-related differences in cue weighting might not be found in this real-world simulation; and (3) Children would experience greater masking than adults. Results showed: (1) no increase for any age listeners in the weighting of vocalic duration in noise; (2) age-related differences in the weighting of cues in both quiet and noise; and (3) masking effects for all listeners, but more so for children than adults.

  13. Masking of short stimuli by noises with spiked spectra: I. Compressive nonlinearity of cochlea and evaluation of frequency resolution

    NASA Astrophysics Data System (ADS)

    Rimskaya-Korsakova, L. K.; Lalayants, M. R.; Supin, A. Ya.; Tavartkiladze, G. A.

    2011-01-01

    A psychoacoustic method for measuring masking thresholds based on the application of single-type stimuli and maskers intended for revealing compressive nonlinearity of displacements of the cochlea basila membrane and evaluation of the frequency resolution of hearing in a narrow frequency range near the central frequency of the stimulus is considered. High-frequency pulses with an envelope in the form of a Gaussian function with a sinusoidal filling with the frequency band corresponding to the width of the critical hearing band have been used as stimuli (referred to as compact). Noises with a spike structure of the amplitude spectrum with a limited frequency band width served as maskers. With the central frequencies of stimuli and maskers being equal, a band noise with the central frequency corresponding with a spike of an indented spectrum was called an on(rip)-frequency masker, while that with the central frequency corresponding to a dip in an indented spectrum was called an off(rip)-frequency masker. The central frequencies and frequency bands of the stimuli and maskers were 4 kHz and 1000 Hz, respectively. The spike (dip) frequencies of an indented amplitude spectrum of a masker were 1000 Hz. In the case of successive and simultaneous masking, the dependences of the thresholds of off(rip)-frequency masking of compact stimuli on the masker level revealed compressive nonlinearity of basila membrane displacements. However, threshold on(rip)/off(rip)-frequency masking differences visualized it much better. The estimates of the frequency resolution obtained under conditions of simultaneous masking of compact stimuli during variations in the frequency of spikes of indented masker spectra of low and medium levels corresponded to the width of the critical hearing band measured using a classical method of tone masking by a pair of narrow-band noise maskers. Within the spike frequency range of 500-2000 Hz, the steepness of the dependence of off(rip)-masking of compact

  14. MaskDensity14: An R package for the density approximant of a univariate based on noise multiplied data

    NASA Astrophysics Data System (ADS)

    Lin, Yan-Xia; Fielding, Mark James

    2015-12-01

    Lin (2014) developed a framework of the method of the sample-moment-based density approximant, for estimating the probability density function of microdata based on noise multiplied data. Theoretically, it provides a promising method for data users in generating the synthetic data of the original data without accessing the original data; however, technical issues can cause problems implementing the method. In this paper, we describe a software package called MaskDensity14, written in the R language, that uses a computational approach to solve the technical issues and makes the method of the sample-moment-based density approximant feasible. MaskDensity14 has applications in many areas, such as sharing clinical trial data and survey data without releasing the original data.

  15. Noise. Ag Ed Environmental Education Series.

    ERIC Educational Resources Information Center

    Tulloch, Rodney W.

    Noise is the subject of the student resource unit to be used with high school vocational agriculture students. The nature of noise as a phenomenon and as a problem is clarified. Sources of noise pollution and the decibel levels they produce are described. Among the effects of noise pollution discussed are hearing loss, annoyance, and accidental…

  16. Strategic environmental noise mapping: methodological issues concerning the implementation of the EU Environmental Noise Directive and their policy implications.

    PubMed

    Murphy, E; King, E A

    2010-04-01

    This paper explores methodological issues and policy implications concerning the implementation of the EU Environmental Noise Directive (END) across Member States. Methodologically, the paper focuses on two key thematic issues relevant to the Directive: (1) calculation methods and (2) mapping methods. For (1), the paper focuses, in particular, on how differing calculation methods influence noise prediction results as well as the value of the EU noise indicator L(den) and its associated implications for comparability of noise data across EU states. With regard to (2), emphasis is placed on identifying the issues affecting strategic noise mapping, estimating population exposure, noise action planning and dissemination of noise mapping results to the general public. The implication of these issues for future environmental noise policy is also examined.

  17. Reducing environmental noise impacts: A USAREUR noise-management program handbook. Final report

    SciTech Connect

    Feather, T.D.; Shekell, T.K.

    1991-06-01

    Noise pollution is a major environmental problem faced by the U.S. Army in Europe. Noise-related complaints from German citizens can escalate into intense political issues in German communities. This in turn hampers efficient operation of military training and often times threatens the Army's mission. In order to remedy these problems, USAREUR has developed a noise management program. A successful noise management program will limit the impact of unavoidable noise on the populace. This report, a component of the noise management program, is a reference document for noise management planning. It contains guidelines and rules-of-thumb for noise management. This document contains procedures which operation and training level personnel can understand and apply in their day to day noise management planning. Noise mitigation tips are given. Basic technical information that will aid in understanding noise mitigation is provided along with noise management through land use planning. Noise management for specific components of the military community, (airfields, base operations, training areas, and housing and recreation areas) are addressed. The nature of noise generated, means of noise abatement at the source, path, and receiver (both physical and organizational/public relations methods), and a case study example are described.

  18. Colloquium: Protecting quantum information against environmental noise

    NASA Astrophysics Data System (ADS)

    Suter, Dieter; Álvarez, Gonzalo A.

    2016-10-01

    Quantum technologies represent a rapidly evolving field in which the specific properties of quantum mechanical systems are exploited to enhance the performance of various applications such as sensing, transmission, and processing of information. Such devices can be useful only if the quantum systems also interact with their environment. However, the interactions with the environment can degrade the specific quantum properties of these systems, such as coherence and entanglement. It is therefore essential that the interaction between a quantum system and the environment is controlled in such a way that the unwanted effects of the environment are suppressed while the necessary interactions are retained. This Colloquium gives an overview, aimed at newcomers to this field, of some of the challenges that need to be overcome to achieve this goal. A number of techniques have been developed for this purpose in different areas of physics including magnetic resonance, optics, and quantum information. They include the application of static or time-dependent fields to the quantum system, which are designed to average the effect of the environmental interactions to zero. Quantum error correction schemes were developed to detect and eliminate certain errors that occur during the storage and processing of quantum information. In many physical systems, it is useful to use specific quantum states that are intrinsically less susceptible to environmental noise for encoding the quantum information. The dominant contribution to the loss of information is pure dephasing, i.e., through the loss of coherence in quantum mechanical superposition states. Accordingly, most schemes for reducing loss of information focus on dephasing processes. This is also the focus of this Colloquium.

  19. Environmental noise and human prenatal growth

    SciTech Connect

    Schell, L.M.

    1981-09-01

    To determine whether chronic exposure to relatively loud noise has demonstrable biological effects in humans, a study was conducted on the effect of mother's exposure to airport noise while pregnant, and of social and biological characteristics of the family upon birthweight and gestation length. The sample of births was drawn from a community located adjacent to an international airport in the U.S., where noise levels had been measured previously. Mother's noise exposure was based upon noise levels near her residence in the community while she was pregnant. Data from 115 births were used, these being from mothers whose noise exposure history was most complete throughout the pregnancy. Using multivariate analysis to correct for family characteristics, the partial correlation coefficient for noise exposure and gestation length was negative, large, and significant in girls (r . -0.49, p less than 0.001). In boys the partial correlation coefficient was also negative but was smaller and did not quite reach statistical significance. Partial correlations with birthweight were smaller in both boys and girls and not significant. These results agree best with previous studies that suggest that noise may reduce prenatal growth. The size of the observed effects may be related to a conservative research design biased towards underestimation, as well as to the real effects of noise upon human prenatal growth.

  20. Effects of the intensity of masking noise on ear canal recorded low-frequency cochlear microphonic waveforms in normal hearing subjects.

    PubMed

    Zhang, Ming

    2014-07-01

    Compared to auditory brainstem responses (ABRs), cochlear microphonics (CMs) may be more appropriate to serve as a supplement to the test of otoacoustic emissions (OAEs). Researchers have shown that low-frequency CMs from the apical cochlea are measurable at the tympanic membrane using high-pass masking noise. Our objective is to study the effect of such noise at different intensities on low-frequency CMs recorded at the ear canal, which is not completely known. Six components were involved in this CM measurement including an ear canal electrode (1), a relatively long and low-frequency toneburst (2), and high-pass masking noise at different intensities (3). The rest components include statistical analysis based on multiple human subjects (4), curve modeling based on amplitudes of CM waveforms (CMWs) and noise intensity (5), and a technique based on electrocochleography (ECochG or ECoG) (6). Results show that low-frequency CMWs appeared clearly. The CMW amplitude decreased with an increase in noise level. It decreased first slowly, then faster, and finally slowly again. In conclusion, when masked with high-pass noise, the low-frequency CMs are measurable at the human ear canal. Such noise reduces the low-frequency CM amplitude. The reduction is noise-intensity dependent but not completely linear. The reduction may be caused by the excited basal cochlea which the low-frequency has to travel and pass through. Although not completely clear, six mechanisms related to such reduction are discussed.

  1. Influence of environmental noise on the weak value amplification

    NASA Astrophysics Data System (ADS)

    Zhu, Xuannmin; Zhang, Yu-Xiang

    2016-08-01

    Quantum systems are always disturbed by environmental noise. We have investigated the influence of the environmental noise on the amplification in weak measurements. Three typical quantum noise processes are discussed in this article. The maximum expectation values of the observables of the measuring device decrease sharply with the strength of the depolarizing and phase damping channels, while the amplification effect of weak measurement is immune to the amplitude damping noise. To obtain significantly amplified signals, we must ensure that the preselection quantum systems are kept away from the depolarizing and phase damping processes.

  2. Joint Service Aircrew Mask (JSAM) - Strategic Aircraft (SA): Noise Attenuation Performance

    DTIC Science & Technology

    2015-08-25

    Acoustic Test Fixture Procedures for the Bose A-20 with and without the JSAM-SA. The addition of the JSAM-SA to all headsets measured for this study...Loss of Hearing Protection Devices in Continuous or Impulsive Noise Using Microphone-in-Real-Ear (MIRE) or Acoustic Test Fixture Procedures2 for the...Continuous or Impulsive Noise Using Microphone-in-Real- Ear (MIRE) or Acoustic Test Fixture Procedures

  3. Auditory Masking Patterns in Bottlenose Dolphins from Anthropogenic and Natural Noise Sources

    DTIC Science & Technology

    2012-09-30

    124(1), 625-633. 11 Erbe, C. (2008). Critical ratios of beluga whales (Delphinapterus leucas) and masked signal duration. Journal of the Acoustical...each of the three whistle-like sounds in FIG 2. For example, when the sound in FIG. 2A was presented, the dolphin was trained to swim and touch a...nylon rope (FIG. 3). If the sound in FIG. 2B was presented, the dolphin swam and touched a water filled aluminum bottle. All three signals had identical

  4. Environmental noise-a challenge for an acoustical engineer

    NASA Astrophysics Data System (ADS)

    Genuit, Klaus

    2003-10-01

    People live in a landscape full of noises which are composed of both natural environmental noises and technically created sounds. Regarding environmental noise, more and more people feel heavily annoyed by noises. Noise is defined as an audible sound which either disturbs the silence or an intentional sound listening or leads to annoyance. Thus, it is clearly defined that the assignment of noise cannot be reduced to simple determining objective parameters such as the A-weighted sound pressure level or the equivalent continuous sound pressure level. The question of whether a sound is judged as noise can only be made after the transformation from the sound event into an auditory event has been accomplished. The evaluation of noise depends on the physical characteristics of the sound event, on the psycho-acoustical features of the human ear, as well as on the psychological aspects of man. For the acoustical design of environmental noise and in order to create a better soundscape the acoustical engineer has to consider these aspects. That means a specific challenge for the sound engineering.

  5. Time course of a perceptual enhancement effect for noise-masked speech in reverberant environments.

    PubMed

    Brandewie, Eugene; Zahorik, Pavel

    2013-08-01

    Speech intelligibility has been shown to improve with prior exposure to a reverberant room environment [Brandewie and Zahorik (2010). J. Acoust. Soc. Am. 128, 291-299] with a spatially separated noise masker. Here, this speech enhancement effect was examined in multiple room environments using carrier phrases of varying lengths in order to control the amount of exposure. Speech intelligibility enhancement of between 5% and 18% was observed with as little as 850 ms of exposure, although the effect's time course varied considerably with reverberation and signal-to-noise ratio. In agreement with previous work, greater speech enhancement was found for reverberant environments compared to anechoic space.

  6. Tackling the Combined Effects of Reverberation and Masking Noise Using Ideal Channel Selection

    ERIC Educational Resources Information Center

    Hazrati, Oldooz; Loizou, Philipos C.

    2012-01-01

    Purpose: In this article, a new signal-processing algorithm is proposed and evaluated for the suppression of the combined effects of reverberation and noise. Method: The proposed algorithm decomposes, on a short-term basis (every 20 ms), the reverberant stimuli into a number of channels and retains only a subset of the channels satisfying a…

  7. The roles of voice onset time and F0 in stop consonant voicing perception: Effects of masking noise and low-pass filtering

    PubMed Central

    Winn, Matthew B.; Chatterjee, Monita; Idsardi, William J.

    2013-01-01

    Purpose The contributions of voice onset time (VOT) and fundamental frequency (F0) were evaluated for the perception of voicing in syllable-initial stop consonants in words that were low-pass filtered and/or masked by speech-shaped noise. It was expected that listeners would rely less on VOT and more on F0 in these degraded conditions. Method Twenty young normal-hearing listeners identified modified natural speech tokens that varied by VOT and F0 in several conditions of low-pass filtering and masking noise. Stimuli included /b/-/p/ and /d/-/t/ continua that were presented in separate blocks. Identification results were modeled using mixed-effects logistic regression. Results When speech was filtered and/or masked by noise, listeners’ voicing perceptions were driven less by VOT and more by F0. Speech-shaped masking noise exerted greater effects on the /b/-/p/ contrast, while low-pass filtering exerted greater effects on the /d/-/t/ contrast, consistent with the acoustics of these contrasts. Conclusion Listeners can adjust their use of acoustic-phonetic cues in a dynamic way that is appropriate for challenging listening conditions; cues that are less influential in ideal conditions can gain priority in challenging conditions. PMID:23785185

  8. The 'shell effect': music from environmental noise

    NASA Astrophysics Data System (ADS)

    Diodati, Paolo

    2005-02-01

    The 'shell effect' can be used to play music with a pleasant and characteristic timbre. If you place a sensitive microphone at the rim of pipes of suitable length and diameter to obtain resonance frequencies, ambient noise will produce musical notes. The corresponding optical effect, i.e. extracting visible light from ambient radiation considered dark by the human eye, is also discussed.

  9. LCP-10 Intelligibility of Oxygen Masks and Microphones in Aircraft Noise

    DTIC Science & Technology

    1988-10-24

    REPORT NUMBER( S ) AAMRL-TR-88-048 f NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION arry G . Armstrong (if...OH TALJE/LISTtER IHTELLIGIBILITY (PEIRCNT CORRECT) S &LQ A& TQLN 7S % Ie It a8 5 95 185 115 NOISE LEL ( d ) FIGURE 11. ILLUSTRATION OF THE RELATIVE...YNAMICS AND IIIOENGINEERING DIVISION IAIRY G . A RMSTRONG AEROSPACE MEDICAL RESEARCHI IABOiAT RY OCIOBER 1988 SUMMARY REPORT FOR OCTOBER 1986

  10. Tackling the combined effects of reverberation and masking noise using ideal channel selection

    PubMed Central

    Hazrati, Oldooz

    2012-01-01

    Purpose A new signal processing algorithm is proposed and evaluated in this study for the suppression of the combined effects of reverberation and noise. Method The proposed algorithm decomposes, on a short-term basis (every 20 ms), the reverberant stimuli into a number of channels and retains only a subset of the channels satisfying a signal-to-reverberant ratio (SRR) criterion. The construction of this criterion assumes access to a priori knowledge of the target (anechoic) signal and the aim of the present study is to assess the full potential of the proposed channel-selection algorithm assuming that this criterion can be estimated accurately. Listening tests were conducted with normal-hearing listeners to assess the performance of the proposed algorithm in highly reverberant conditions (T60 = 1.0 s) which included additive noise at 0 and 5 dB SNR. Results A substantial gain in intelligibility was obtained in both reverberant and combined reverberant and noise conditions. The mean intelligibility scores improved by 44 and 33 percentage points at 0 and 5 dB SNR reverberant+noise conditions. Feature analysis of the consonant confusion matrices revealed that the transmission of voicing information was most negatively affected, followed by manner and place of articulation. Conclusions The proposed algorithm was found to produce substantial gains in intelligibility, and this benefit was attributed to the ability of the proposed SRR criterion to accurately detect voiced/unvoiced boundaries. Detection of those boundaries is postulated to be critical for better perception of voicing information and manner of articulation. PMID:22232411

  11. Mapping urban environmental noise: a land use regression method.

    PubMed

    Xie, Dan; Liu, Yi; Chen, Jining

    2011-09-01

    Forecasting and preventing urban noise pollution are major challenges in urban environmental management. Most existing efforts, including experiment-based models, statistical models, and noise mapping, however, have limited capacity to explain the association between urban growth and corresponding noise change. Therefore, these conventional methods can hardly forecast urban noise at a given outlook of development layout. This paper, for the first time, introduces a land use regression method, which has been applied for simulating urban air quality for a decade, to construct an urban noise model (LUNOS) in Dalian Municipality, Northwest China. The LUNOS model describes noise as a dependent variable of surrounding various land areas via a regressive function. The results suggest that a linear model performs better in fitting monitoring data, and there is no significant difference of the LUNOS's outputs when applied to different spatial scales. As the LUNOS facilitates a better understanding of the association between land use and urban environmental noise in comparison to conventional methods, it can be regarded as a promising tool for noise prediction for planning purposes and aid smart decision-making.

  12. Individual right whales call louder in increased environmental noise.

    PubMed

    Parks, Susan E; Johnson, Mark; Nowacek, Douglas; Tyack, Peter L

    2011-02-23

    The ability to modify vocalizations to compensate for environmental noise is critical for successful communication in a dynamic acoustic environment. Many marine species rely on sound for vital life functions including communication, navigation and feeding. The impacts of significant increases in ocean noise levels from human activities are a current area of concern for the conservation of marine mammals. Here, we document changes in calling behaviour by individual endangered North Atlantic right whales (Eubalaena glacialis) in increased background noise. Right whales, like several bird and primate species, respond to periods of increased noise by increasing the amplitude of their calls. This behaviour may help maintain the communication range with conspecifics during periods of increased noise. These call modifications have implications for conservation efforts for right whales, affecting both the way whales use sound to communicate and our ability to detect them with passive acoustic monitoring systems.

  13. Individual right whales call louder in increased environmental noise

    PubMed Central

    Parks, Susan E.; Johnson, Mark; Nowacek, Douglas; Tyack, Peter L.

    2011-01-01

    The ability to modify vocalizations to compensate for environmental noise is critical for successful communication in a dynamic acoustic environment. Many marine species rely on sound for vital life functions including communication, navigation and feeding. The impacts of significant increases in ocean noise levels from human activities are a current area of concern for the conservation of marine mammals. Here, we document changes in calling behaviour by individual endangered North Atlantic right whales (Eubalaena glacialis) in increased background noise. Right whales, like several bird and primate species, respond to periods of increased noise by increasing the amplitude of their calls. This behaviour may help maintain the communication range with conspecifics during periods of increased noise. These call modifications have implications for conservation efforts for right whales, affecting both the way whales use sound to communicate and our ability to detect them with passive acoustic monitoring systems. PMID:20610418

  14. Active Shielding and Control of Environmental Noise

    NASA Technical Reports Server (NTRS)

    Tsynkov, S. V.

    2001-01-01

    In the framework of the research project supported by NASA under grant # NAG-1-01064, we have studied the mathematical aspects of the problem of active control of sound, i.e., time-harmonic acoustic disturbances. The foundations of the methodology are described in our paper [1]. Unlike. many other existing techniques, the approach of [1] provides for the exact volumetric cancellation of the unwanted noise on a given predetermined region airspace, while leaving unaltered those components of the total acoustic field that are deemed as friendly. The key finding of the work is that for eliminating the unwanted component of the acoustic field in a given area, one needs to know relatively little; in particular, neither the locations nor structure nor strength of the exterior noise sources need to be known. Likewise, there is no need to know the volumetric properties of the supporting medium across which the acoustic signals propagate, except, maybe, in a narrow area of space near the perimeter of the protected region. The controls are built based solely on the measurements performed on the perimeter of the domain to be shielded; moreover, the controls themselves (i.e., additional sources) are concentrated also only on or near this perimeter. Perhaps as important, the measured quantities can refer to the total acoustic field rather than to its unwanted component only, and the methodology can automatically distinguish between the two. In [1], we have constructed the general solution for controls. The apparatus used for deriving this general solution is closely connected to the concepts of generalized potentials and boundary projections of Calderon's type. For a given total wave field, the application of a Calderon's projection allows one to definitively tell between its incoming and outgoing components with respect to a particular domain of interest, which may have arbitrary shape. Then, the controls are designed so that they suppress the incoming component for the domain

  15. Noise Attenuation Performance of the Joint Service Aircrew Mask (JSAM) - Joint Strike Fighter (JSF) with the Lightning II Generation II Helmet

    DTIC Science & Technology

    2012-04-01

    1 Figure 2. a. F-35 Lightning II Gen II HMD b. Original ANR Earcups...Integrated System Ltd (HISL) active noise reduction ( ANR ) earcups (part number JS02591, Figure 2b), and a MBU-23/P oxygen mask with customized...F-35 Lightning II Gen II HMD b. Original ANR Earcups Table 1. JSAM-JSF Requirement (baseline Gen II HMD total attenuation data collected in

  16. Cardiovascular effects of environmental noise: research in Austria.

    PubMed

    Lercher, Peter; Botteldooren, Dick; Widmann, Ulrich; Uhrner, Ulrich; Kammeringer, Ewald

    2011-01-01

    Cardiovascular effects of noise rank second in terms of disability-adjusted life year (DALYs) after annoyance. Although research during the past decade has consolidated the available data base, the most recent meta-analysis still shows wide confidence intervals - indicating imprecise information for public health risk assessment. The alpine area of Tyrol in the Austrian part of the Alps has experienced a massive increase in car and heavy goods traffic (road and rail) during the last 35 years. Over the past 25 years small-, middle-, and large-sized epidemiological health surveys have been conducted - mostly within the framework of environmental health impact assessments. By design, these studies have emphasized a contextually driven environmental stress perspective, where the adverse health effects on account of noise are studied in a broader framework of environmental health, susceptibility, and coping. Furthermore, innovative exposure assessment strategies have been implemented. This article reviews the existing knowledge from these studies over time, and presents the exposure-response curves, with and without interaction assessment, based on standardized re-analyses and discusses it in the light of past and current cardiovascular noise effects research. The findings support relevant moderation by age, gender, and family history in nearly all studies and suggest a strong need for consideration of non-linearity in the exposure-response analyses. On the other hand, air pollution has not played a relevant role as a moderator in the noise-hypertension or the noise-angina pectoris relationship. Finally, different noise modeling procedures can introduce variations in the exposure response curves, with substantive consequences for public health risk assessment of noise exposure.

  17. Environmental Pollution: Noise Pollution - Sonic Boom. Volume I.

    ERIC Educational Resources Information Center

    Defense Documentation Center, Alexandria, VA.

    The unclassified, annotated bibliography is Volume I of a two-volume set on Noise Pollution - Sonic Boom in a series of scheduled bibliographies on Environmental Pollution. Volume II is Confidential. Corporate author-monitoring agency, subject, title, contract, and report number indexes are included. (Author/JR)

  18. Assessing the environmental impacts of aircraft noise and emissions

    NASA Astrophysics Data System (ADS)

    Mahashabde, Anuja; Wolfe, Philip; Ashok, Akshay; Dorbian, Christopher; He, Qinxian; Fan, Alice; Lukachko, Stephen; Mozdzanowska, Aleksandra; Wollersheim, Christoph; Barrett, Steven R. H.; Locke, Maryalice; Waitz, Ian A.

    2011-01-01

    With the projected growth in demand for commercial aviation, many anticipate increased environmental impacts associated with noise, air quality, and climate change. Therefore, decision-makers and stakeholders are seeking policies, technologies, and operational procedures that balance environmental and economic interests. The main objective of this paper is to address shortcomings in current decision-making practices for aviation environmental policies. We review knowledge of the noise, air quality, and climate impacts of aviation, and demonstrate how including environmental impact assessment and quantifying uncertainties can enable a more comprehensive evaluation of aviation environmental policies. A comparison is presented between the cost-effectiveness analysis currently used for aviation environmental policy decision-making and an illustrative cost-benefit analysis. We focus on assessing a subset of the engine NO X emissions certification stringency options considered at the eighth meeting of the International Civil Aviation Organization’s Committee on Aviation Environmental Protection. The FAA Aviation environmental Portfolio Management Tool (APMT) is employed to conduct the policy assessments. We show that different conclusions may be drawn about the same policy options depending on whether benefits and interdependencies are estimated in terms of health and welfare impacts versus changes in NO X emissions inventories as is the typical practice. We also show that these conclusions are sensitive to a variety of modeling uncertainties. While our more comprehensive analysis makes the best policy option less clear, it represents a more accurate characterization of the scientific and economic uncertainties underlying impacts and the policy choices.

  19. Rhythmic masking release: Contribution of cues for perceptual organization to the cross-spectral fusion of concurrent narrow-band noises

    NASA Astrophysics Data System (ADS)

    Turgeon, Martine; Bregman, Albert S.; Ahad, Pierre A.

    2002-04-01

    The contribution of temporal asynchrony, spatial separation, and frequency separation to the cross-spectral fusion of temporally contiguous brief narrow-band noise bursts was studied using the Rhythmic Masking Release paradigm (RMR). RMR involves the discrimination of one of two possible rhythms, despite perceptual masking of the rhythm by an irregular sequence of sounds identical to the rhythmic bursts, interleaved among them. The release of the rhythm from masking can be induced by causing the fusion of the irregular interfering sounds with concurrent ``flanking'' sounds situated in different frequency regions. The accuracy and the rated clarity of the identified rhythm in a 2-AFC procedure were employed to estimate the degree of fusion of the interferring sounds with flanking sounds. The results suggest that while synchrony fully fuses short-duration noise bursts across frequency and across space (i.e., across ears and loudspeakers), an asynchrony of 20-40 ms produces no fusion. Intermediate asynchronies of 10-20 ms produce partial fusion, where the presence of other cues is critical for unambiguous grouping. Though frequency and spatial separation reduced fusion, neither of these manipulations was sufficient to abolish it. For the parameters varied in this study, stimulus onset asynchrony was the dominant cue determining fusion, but there were additive effects of the other cues. Temporal synchrony appears to be critical in determining whether brief sounds with abrupt onsets and offsets are heard as one event or more than one.

  20. Poor environmental tracking can make extinction risk insensitive to the colour of environmental noise.

    PubMed

    van de Pol, Martijn; Vindenes, Yngvild; Sæther, Bernt-Erik; Engen, Steinar; Ens, Bruno J; Oosterbeek, Kees; Tinbergen, Joost M

    2011-12-22

    The relative importance of environmental colour for extinction risk compared with other aspects of environmental noise (mean and interannual variability) is poorly understood. Such knowledge is currently relevant, as climate change can cause the mean, variability and temporal autocorrelation of environmental variables to change. Here, we predict that the extinction risk of a shorebird population increases with the colour of a key environmental variable: winter temperature. However, the effect is weak compared with the impact of changes in the mean and interannual variability of temperature. Extinction risk was largely insensitive to noise colour, because demographic rates are poor in tracking the colour of the environment. We show that three mechanisms-which probably act in many species-can cause poor environmental tracking: (i) demographic rates that depend nonlinearly on environmental variables filter the noise colour, (ii) demographic rates typically depend on several environmental signals that do not change colour synchronously, and (iii) demographic stochasticity whitens the colour of demographic rates at low population size. We argue that the common practice of assuming perfect environmental tracking may result in overemphasizing the importance of noise colour for extinction risk. Consequently, ignoring environmental autocorrelation in population viability analysis could be less problematic than generally thought.

  1. Potential Application of Environmental Noise Recordings in Geoarchaeological Site Characterization

    NASA Astrophysics Data System (ADS)

    Di Luzio, E.

    2015-12-01

    Environmental noise recordings are commonly applied in seismic microzonation studies. By calculating the H/V spectral ratio, the fundamental frequency of soft terrains overlying a rigid bedrock can be determined (Nakamura (1989). In such a simple two-layer system, equation f = n Vs/4H (1) links the resonance frequency "f" to the thickness "H" and shear waves velocity "Vs "of the resonating layer. In recent years, this methodology has been applied generally to obtain information on the seismostratigraphy of an investigated site in different environmental context. In this work, its potential application in the characterization of archaeological features hosted in shallow geological levels is discussed. Field cases are identified in the Appia Antica archaeological site which is placed in central Italy. Here, acknowledged targets correspond to: i) empty tanks carved by the Romans into Cretaceous limestone in the IV-III cen. BC and ii): the basaltic stone paving of the ancient road track which is locally buried beneath colluvial deposits. Narrowly-spaced recordings of environmental noise were carried using a portable digital seismograph equipped with three electrodynamic orthogonal sensors (velocimeters) responding in the band 0.1 ÷1024 Hz and adopting a sampling frequency of 256 Hz.. Results are discussed in terms of absolute H/V values and related distribution maps in the very high-frequency interval of 10-40Hz. In the tanks hosting area, interpolation of H/V maximum values around 13Hz matches caves location and alignment, which is also evidenced by clear inversions (H/V<1) at lower frequencies (10-1Hz). Correlation between H/V peaks and the top surface of the buried stone paving along the prosecution of the road track is even more straightforward. Finally, the depth variations of the tank roofs and the basaltic paving were reconstructed combining in equation (1) results of noise recordings with borehole data and geophysical surveys (SASW analysis).

  2. Stochastic Liouville equation for particles driven by dichotomous environmental noise

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.

    2017-01-01

    We analyze the stochastic dynamics of a large population of noninteracting particles driven by a global environmental input in the form of a dichotomous Markov noise process (DMNP). The population density of particle states evolves according to a stochastic Liouville equation with respect to different realizations of the DMNP. We then exploit the connection with previous work on diffusion in randomly switching environments, in order to derive moment equations for the distribution of solutions to the stochastic Liouville equation. We illustrate the theory by considering two simple examples of dichotomous flows, a velocity jump process and a two-state gene regulatory network. In both cases we show how the global environmental input induces statistical correlations between different realizations of the population density.

  3. Valuing Quiet: An economic assessment of US environmental noise as a cardiovascular health hazard

    PubMed Central

    Swinburn, Tracy K.; Hammer, Monica S.; Neitzel, Richard L.

    2016-01-01

    Introduction Environmental noise pollution increases the risk for hearing loss, stress, sleep disruption, annoyance, cardiovascular disease, and has other adverse health impacts. Recent (2013) estimates suggest that over 100 million Americans are exposed to unhealthy levels of noise. Given the pervasive nature and significant health effects of environmental noise pollution, the corresponding economic impacts may be significant. Methods This 2014 economic assessment developed a new approach to estimate the impact of environmental noise on the prevalence and cost of key components of hypertension and cardiovascular disease in the US. By placing environmental noise in context with comparable environmental pollutants, this approach can inform public health law, planning and policy. The effects of hypothetical national-scale changes in environmental noise levels on the prevalence and corresponding costs of hypertension and coronary heart disease are estimated, with the caveat that the national-level US noise data our exposure estimates were derived from are >30 years old. Results The analyses suggest that a 5 dB noise reduction scenario would reduce the prevalence of hypertension by 1.4% and coronary heart disease by 1.8%. The annual economic benefit is estimated at $3.9 billion. Conclusions These findings suggest significant economic impacts from environmental noise-related cardiovascular disease. Given these initial findings, noise may deserve increased priority and research as an environmental health hazard. PMID:26024562

  4. Masking by Gratings Predicted by an Image Sequence Discriminating Model: Testing Models for Perceptual Discrimination Using Repeatable Noise

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Null, Cynthia H. (Technical Monitor)

    1998-01-01

    Adding noise to stimuli to be discriminated allows estimation of observer classification functions based on the correlation between observer responses and relevant features of the noisy stimuli. Examples will be presented of stimulus features that are found in auditory tone detection and visual vernier acuity. using the standard signal detection model (Thurstone scaling), we derive formulas to estimate the proportion of the observers decision variable variance that is controlled by the added noise. one is based on the probability of agreement of the observer with him/herself on trials with the same noise sample. Another is based on the relative performance of the observer and the model. When these do not agree, the model can be rejected. A second derivation gives the probability of agreement of observer and model when the observer follows the model except for internal noise. Agreement significantly less than this amount allows rejection of the model.

  5. Species coexistence in a neutral dynamics with environmental noise.

    PubMed

    Hidalgo, Jorge; Suweis, Samir; Maritan, Amos

    2017-01-21

    Environmental fluctuations have important consequences in the organization of ecological communities, and understanding how such a variability influences the biodiversity of an ecosystem is a major question in ecology. In this paper, we analyze the case of two species competing for the resources within the framework of the neutral theory in the presence of environmental noise, devoting special attention on how such a variability modulates species fitness. The environment is dichotomous and stochastically alternates between periods favoring one of the species while disfavoring the other one, preserving neutrality on the long term. We study two different scenarios: in the first one species fitness varies linearly with the environment, and in the second one the effective fitness is re-scaled by the total fitness of the individuals competing for the same resource. We find that, in the former case environmental fluctuations always reduce the time of species coexistence, whereas such a time can be enhanced or reduced in the latter case, depending on the correlation time of the environment. This phenomenon can be understood as a direct consequence of Chesson's storage effect.

  6. Quantum correlations of identical particles subject to classical environmental noise

    NASA Astrophysics Data System (ADS)

    Beggi, Andrea; Buscemi, Fabrizio; Bordone, Paolo

    2016-09-01

    In this work, we propose a measure for the quantum discord of indistinguishable particles, based on the definition of entanglement of particles given in Wiseman and Vaccaro (Phys Rev Lett 91:097902, 2003. doi: 10.1103/PhysRevLett.91.097902). This discord of particles is then used to evaluate the quantum correlations in a system of two identical bosons (fermions), where the particles perform a quantum random walk described by the Hubbard Hamiltonian in a 1D lattice. The dynamics of the particles is either unperturbed or subject to a classical environmental noise—such as random telegraph, pink or brown noise. The observed results are consistent with those for the entanglement of particles, and we observe that on-site interaction between particles have an important protective effect on correlations against the decoherence of the system.

  7. [Influence of environmental noise on sleep quality and sleeping disorders-implications for health].

    PubMed

    Kohlhuber, M; Bolte, G

    2011-12-01

    Environmental noise is a well-known risk factor influencing sleep-wake behavior and sleep quality. Epidemiologic studies have shown that environmental noise is regarded as the most annoying environmental factor. Noise causes modifications in physiologic and mental functions and may result in health outcomes like elevated blood pressure and ischemic heart disease. Reactions to high sound levels during sleep are decreased sleep intensity, arousals, and increased stress hormone secretion. Effects of poor sleep quality are reduced cognitive performance, tiredness, and psychosomatic symptoms. Long-term consequences of recurrent sleep loss due to environmental noise may be heart disease and increased medication intake. Arousals occur especially due to single noise events and intermittent noise. Laboratory and field studies showed no habituation of physiologic parameters to high sound levels. Sleep is especially sensitive to noise; therefore, sound levels during nighttime should be much lower than during daytime.

  8. [Environmental noise and satisfaction with area of residence].

    PubMed

    Maschke, C; Laussmann, D; Eis, D; Wolf, U

    1999-12-01

    In the German National Health Interview and Examination Survey, more than one third, i.e. 36.2% of persons interviewed on the matter of noise nuisance in their homes attributed to outdoor noise confirmed the occurrence of noise. Regarding this result only small and statistically insignificant differences have been assessed in East and West Germany. The frequency of affirmative answers given by German women, ages 20-39, was significantly higher as compared to men in the same ages bracket. Regarding the dominant noise effects in their home, 87% of persons affected mentioned traffic noise as a source. In the second place neighbour noise has been reported by 32%. Aircraft and railway noises percepted by 20%, are in the third and fourth place. Particularly severe indoor noise effects, i.e. persisting noise during the night, are accompanied with clearly increased discontent regarding the home and living area.

  9. Noise Pollution, AMA Congress on Environmental Health (6th, Chicago, Illinois, April 28-29, 1969).

    ERIC Educational Resources Information Center

    American Medical Association, Chicago, IL.

    Contained are 15 papers presented at the sixth annual AMA Congress on Environmental Health. Three papers are concerned with noise induced hearing loss as it relates to pathological effects, the role of physicians in workmen's compensation cases, and exposure to steady-state noise. Five papers deal with noise control as it relates to medical…

  10. Physiological functioning of the ear and masking

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The physiological functions of the ear and the role masking plays in speech communication are examined. Topics under investigation include sound analysis of the ear, the aural reflex, and various types of noise masking.

  11. [Summary of ongoing activities on environmental noise and health at the WHO regional office for Europe].

    PubMed

    Héroux, M E; Braubach, M; Dramac, D; Korol, N; Paunovic, E; Zastenskaya, I

    2014-01-01

    The environmental noise is an important public health issue, according to recent assessment of the burden of diseases among environmental health risk factors in order of importance the environmental noise occupies the second place after air pollution. The World Health Organization (WHO) for the first time published its public health recommendations for the environmental noise in 1999 in the "WHO Guidelines for Community Noise (1999)". These recommendations found their development in WHO Night Noise Guidelines for Europe" (2009). From then onward there have been published new important data on the impact of the environmental noise on the health, that stipulated the revision of existing guidelines. Furthermore, both in the European Union (EU) Directive 2002/49/ EC and the Parma Declaration from 2010 there was pointed out the importance of renewal environmental noise recommendations. Responding to appearing interrogation, WHO Regional Office for Europe has recently initiated the process of the elaboration of new guiding principles known as "WHO Environmental Noise Guidelines for the European Region". The Guidelines will include a systematic review of most critical or important health consequences and also concentrate on health benefits of measures for the reducing noise levels. The Guidelines will consider noise coming from various noise sources such as aircraft, railroad, personal electronic devices and wind turbines. The Guidelines will also consider the particularity of such accommodations as residences, hospitals, and educational facilities. The work in the mentioned spheres is ongoing and the revised Guidelines are expected to be published in mid-2015. The Guidelines will provide up-to-date information on the health risks related to the environmental noise and evidence-based recommendations in order to support for WHO Member States in their efforts to prevent of the excessive noise and the struggle with their negative impact.

  12. Noise impact on wildlife: An environmental impact assessment

    NASA Technical Reports Server (NTRS)

    Bender, A.

    1977-01-01

    Various biological effects of noise on animals are discussed and a systematic approach for an impact assessment is developed. Further research is suggested to fully quantify noise impact on the species and its ecosystem.

  13. Construction and application of a questionnaire for the social scientific investigation of environmental noise effects

    NASA Technical Reports Server (NTRS)

    Guski, R.; Wichmann, U.; Rohrmann, B.; Finke, H. O.

    1980-01-01

    A social psychological questionnair has been developed to study the effects of environmental noise and was applied to 636 people living in 19 different areas of Hamburg. The theoretical foundations and the statistical means employed in its development are described. Four main reactions to noise are isolated statistically, and it is determined that these are moderated by several intervening variables, chief of which are coping capacity for noise, the perceived dangerousness of the noise souce, other daily loads and the individual's liability.

  14. Inter-noise 89 - Engineering for environmental noise control; Proceedings of the International Conference on Noise Control Engineering, Newport Beach, CA, Dec. 4-6, 1989. Vols. 1 & 2

    NASA Astrophysics Data System (ADS)

    Maling, George C., Jr.

    Recent advances in noise analysis and control theory and technology are discussed in reviews and reports. Topics addressed include noise generation; sound-wave propagation; noise control by external treatments; vibration and shock generation, transmission, isolation, and reduction; multiple sources and paths of environmental noise; noise perception and the physiological and psychological effects of noise; instrumentation, signal processing, and analysis techniques; and noise standards and legal aspects. Diagrams, drawings, graphs, photographs, and tables of numerical data are provided.

  15. A Comprehensive Approach to Management of Workplace and Environmental Noise at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Cooper, Beth A.

    1995-01-01

    NASA Lewis Research Center is home to more than 100 experimental research testing facilities and laboratories, including large wind tunnels and engine test cells, which in combination create a varied and complex noise environment. Much of the equipment was manufactured prior to the enactment of legislation limiting product noise emissions or occupational noise exposure. Routine facility maintenance and associated construction also contributes to a noise exposure management responsibility which is equal in magnitude and scope to that of several small industrial companies. The Noise Program, centrally managed within the Office of Environmental Programs at LRC, maintains overall responsibility for hearing conservation, community noise control, and acoustical and noise control engineering. Centralized management of the LRC Noise Program facilitates the timely development and implementation of engineered noise control solutions for problems identified via either the Hearing Conservation of Community Noise Program. The key element of the Lewis Research Center Noise Program, Acoustical and Noise Control Engineering Services, is focused on developing solutions that permanently reduce employee and community noise exposure and maximize research productivity by reducing or eliminating administrative and operational controls and by improving the safety and comfort of the work environment. The Hearing Conservation Program provides noise exposure assessment, medical monitoring, and training for civil servant and contractor employees. The Community Noise Program aims to maintain the support of LRC's neighboring communities while enabling necessary research operations to accomplish their programmatic goals. Noise control engineering capability resides within the Noise Program. The noise control engineering, based on specific exposure limits, is a fundamental consideration throughout the design phase of new test facilities, labs, and office buildings. In summary, the Noise Program

  16. Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels.

    PubMed

    Ragettli, Martina S; Goudreau, Sophie; Plante, Céline; Perron, Stéphane; Fournier, Michel; Smargiassi, Audrey

    2015-12-29

    There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels-LAeq24h and day-evening-night equivalent noise levels-Lden) for each study participant was determined using a statistical noise model (land use regression-LUR) that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR) for highly disturbed people of 1.10 (95% CI: 1.07-1.13) and 1.04 (1.02-1.06) per 1 dB(A) Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic.

  17. Environmental Noise Pollution in the United States: Developing an Effective Public Health Response

    PubMed Central

    Hammer, Monica S.; Swinburn, Tracy K.

    2013-01-01

    Background: Tens of millions of Americans suffer from a range of adverse health outcomes due to noise exposure, including heart disease and hearing loss. Reducing environmental noise pollution is achievable and consistent with national prevention goals, yet there is no national plan to reduce environmental noise pollution. Objectives: We aimed to describe some of the most serious health effects associated with noise, summarize exposures from several highly prevalent noise sources based on published estimates as well as extrapolations made using these estimates, and lay out proven mechanisms and strategies to reduce noise by incorporating scientific insight and technological innovations into existing public health infrastructure. Discussion: We estimated that 104 million individuals had annual LEQ(24) levels > 70 dBA (equivalent to a continuous average exposure level of >70 dBA over 24 hr) in 2013 and were at risk of noise-induced hearing loss. Tens of millions more may be at risk of heart disease, and other noise-related health effects. Direct regulation, altering the informational environment, and altering the built environment are the least costly, most logistically feasible, and most effective noise reduction interventions. Conclusion: Significant public health benefit can be achieved by integrating interventions that reduce environmental noise levels and exposures into the federal public health agenda. Citation: Hammer MS, Swinburn TK, Neitzel RL. 2014. Environmental noise pollution in the United States: developing an effective public health response. Environ Health Perspect 122:115–119; http://dx.doi.org/10.1289/ehp.1307272 PMID:24311120

  18. A program to support the full utilization of data from existing social surveys of environmental noise

    NASA Technical Reports Server (NTRS)

    Fields, J. M.

    1980-01-01

    A brief review is presented of a three-part project (partially supported by NASA), which promotes greater utilization of social survey data for gaining new information about human response to environmental noise. The goal is accomplished by (1) publishing a catalog of existing social surveys on environmental noise, (2) establishing a data archive for noise survey data sets, and (3) reanalyzing selected surveys to address substantial and methodological issues. A finding about annoyance scales illustrates the use of a comparative analysis.

  19. Sleep Disturbance from Road Traffic, Railways, Airplanes and from Total Environmental Noise Levels in Montreal.

    PubMed

    Perron, Stéphane; Plante, Céline; Ragettli, Martina S; Kaiser, David J; Goudreau, Sophie; Smargiassi, Audrey

    2016-08-11

    The objective of our study was to measure the impact of transportation-related noise and total environmental noise on sleep disturbance for the residents of Montreal, Canada. A telephone-based survey on noise-related sleep disturbance among 4336 persons aged 18 years and over was conducted. LNight for each study participant was estimated using a land use regression (LUR) model. Distance of the respondent's residence to the nearest transportation noise source was also used as an indicator of noise exposure. The proportion of the population whose sleep was disturbed by outdoor environmental noise in the past 4 weeks was 12.4%. The proportion of those affected by road traffic, airplane and railway noise was 4.2%, 1.5% and 1.1%, respectively. We observed an increased prevalence in sleep disturbance for those exposed to both rail and road noise when compared for those exposed to road only. We did not observe an increased prevalence in sleep disturbance for those that were both exposed to road and planes when compared to those exposed to road or planes only. We developed regression models to assess the marginal proportion of sleep disturbance as a function of estimated LNight and distance to transportation noise sources. In our models, sleep disturbance increased with proximity to transportation noise sources (railway, airplane and road traffic) and with increasing LNight values. Our study provides a quantitative estimate of the association between total environmental noise levels estimated using an LUR model and sleep disturbance from transportation noise.

  20. Public health implications of environmental noise associated with unconventional oil and gas development.

    PubMed

    Hays, Jake; McCawley, Michael; Shonkoff, Seth B C

    2017-02-15

    Modern oil and gas development frequently occurs in close proximity to human populations and increased levels of ambient noise have been documented throughout some phases of development. Numerous studies have evaluated air and water quality degradation and human exposure pathways, but few have evaluated potential health risks and impacts from environmental noise exposure. We reviewed the scientific literature on environmental noise exposure to determine the potential concerns, if any, that noise from oil and gas development activities present to public health. Data on noise levels associated with oil and gas development are limited, but measurements can be evaluated amidst the large body of epidemiology assessing the non-auditory effects of environmental noise exposure and established public health guidelines for community noise. There are a large number of noise dependent and subjective factors that make the determination of a dose response relationship between noise and health outcomes difficult. However, the literature indicates that oil and gas activities produce noise at levels that may increase the risk of adverse health outcomes, including annoyance, sleep disturbance, and cardiovascular disease. More studies that investigate the relationships between noise exposure and human health risks from unconventional oil and gas development are warranted. Finally, policies and mitigation techniques that limit human exposure to noise from oil and gas operations should be considered to reduce health risks.

  1. Manatee (Trichechus manatus) vocalization usage in relation to environmental noise levels.

    PubMed

    Miksis-Olds, Jennifer L; Tyack, Peter L

    2009-03-01

    Noise can interfere with acoustic communication by masking signals that contain biologically important information. Communication theory recognizes several ways a sender can modify its acoustic signal to compensate for noise, including increasing the source level of a signal, its repetition, its duration, shifting frequency outside that of the noise band, or shifting the timing of signal emission outside of noise periods. The extent to which animals would be expected to use these compensation mechanisms depends on the benefit of successful communication, risk of failure, and the cost of compensation. Here we study whether a coastal marine mammal, the manatee, can modify vocalizations as a function of behavioral context and ambient noise level. To investigate whether and how manatees modify their vocalizations, natural vocalization usage and structure were examined in terms of vocalization rate, duration, frequency, and source level. Vocalizations were classified into two call types, chirps and squeaks, which were analyzed independently. In conditions of elevated noise levels, call rates decreased during feeding and social behaviors, and the duration of each call type was differently influenced by the presence of calves. These results suggest that ambient noise levels do have a detectable effect on manatee communication and that manatees modify their vocalizations as a function of noise in specific behavioral contexts.

  2. The hippocampus may be more susceptible to environmental noise than the auditory cortex.

    PubMed

    Cheng, Liang; Wang, Shao-Hui; Huang, Yun; Liao, Xiao-Mei

    2016-03-01

    Noise exposure can cause structural and functional problem in the auditory cortex (AC) and hippocampus, the two brain regions in the auditory and non-auditory systems respectively. The aim of the present study was to explore which one of these two brain regions may be more susceptible to environmental noise. The AC and hippocampus of mice were separated following 1 or 3 weeks exposure to moderate noise (80 dB SPL, 2 h/day). The levels of oxidative stress and tau phosphorylation were then measured to evaluate the effects by noise. Results showed significant peroxidation and tau hyperphosphorylation in the hippocampus with 1 week of noise exposure. However, the AC did not show significant changes until exposure for 3 weeks. These data suggest that although the hippocampus and AC were affected by moderate noise exposure, the hippocampus in the non-auditory system may have been more vulnerable to environmental noise than the AC.

  3. Opportunities for Environmental Noise Mapping in Saudi Arabia: A Case of Traffic Noise Annoyance in an Urban Area in Jeddah City

    PubMed Central

    Zytoon, Mohamed A.

    2016-01-01

    As the traffic and other environmental noise generating activities are growing in The Kingdom of Saudi Arabia (KSA), adverse health and other impacts are expected to develop. The management of such problem involves many actions, of which noise mapping has been proven to be a helpful approach. The objective of the current study was to test the adequacy of the available data in KSA municipalities for generating urban noise maps and to verify the applicability of available environmental noise mapping and noise annoyance models for KSA. Therefore, noise maps were produced for Al-Fayha District in Jeddah City, KSA using commercially available noise mapping software and applying the French national computation method “NMPB” for traffic noise. Most of the data required for traffic noise prediction and annoyance analysis were available, either in the Municipality GIS department or in other governmental authorities. The predicted noise levels during the three time periods, i.e., daytime, evening, and nighttime, were found higher than the maximum recommended levels established in KSA environmental noise standards. Annoyance analysis revealed that high percentages of the District inhabitants were highly annoyed, depending on the type of planning zone and period of interest. These results reflect the urgent need to consider environmental noise reduction in KSA national plans. The accuracy of the predicted noise levels and the availability of most of the necessary data should encourage further studies on the use of noise mapping as part of noise reduction plans. PMID:27187438

  4. Impact of environmental noise on growth and neuropsychological development of newborn rats.

    PubMed

    Zheng, Yanyan; Meng, Meng; Zhao, Congmin; Liao, Wei; Zhang, Yuping; Wang, Liyan; Wen, Enyi

    2014-05-01

    We aimed to investigate the effects of environmental noise exposure on the growth and neuropsychological development in neonatal rats. Twenty-four postnatal 7-day-old Sprague-Dawley rats were randomly assigned into control, high-noise and reduced noise groups. The rats in the high-noise group were exposed to 90 dB white noise, and those in the control group were grown under standard condition, while those in the reduced noise group were exposed to standard condition with sound-absorbing cotton. Ten, 15, and 20 days post noise exposure, both the body weight and length of the rats in high-noise group were lower than those in the control and reduced noise groups, respectively. The secretion of growth hormone was significantly decreased in the rats exposed to high noise environment, compared to those exposed to standard condition and reduced noise. More interestingly, the swimming distance was apparently increased and the swimming speed was significantly decreased in high-noise group compared with those in control and reduced noise groups. Importantly, the mRNA and protein levels of SYP in the rats hippocampus were significantly decreased in high-noise group compare with those in control and reduced noise groups. Similarly, the positive expression of SYP in the CA1 region of hippocampus was also significantly decreased in the high noise group rats. In conclusion, our results demonstrated that high noise exposure could decrease the production of growth hormone and SYP in neonatal rats, which may retard the growth of weight and length and the capability of learning and memory.

  5. Environmental Propagation of Noise in Mines and Nearby Villages: A Study Through Noise Mapping

    PubMed Central

    Manwar, Veena D.; Mandal, Bibhuti B.; Pal, Asim K.

    2016-01-01

    Background: Noise mapping being an established practice in Europe is hardly practiced for noise management in India although it is mandatory in Indian mines as per guidelines of the Directorate General of Mines Safety (DGMS). As a pilot study, noise mapping was conducted in an opencast mine with three different models; one based on the baseline operating conditions in two shifts (Situation A), and two other virtual situations where either production targets were enhanced by extending working hours to three shifts (Situation B) or only by increased mechanization and not changing the duration of work (Situation C). Methods: Noise sources were categorized as point, line, area, and moving sources. Considering measured power of the sources, specific meteorological and geographical parameters, noise maps were generated using Predictor LimA software. Results: In all three situations, Lden values were 95 dB(A) and 70–80 dB(A) near drill machine and haul roads, respectively. Noise contours were wider in Situation C due to increase in frequency of dumpers. Lden values near Shovel 1 and Shovel 2 under Situation B increased by 5 dB and 3 dB, respectively due to expansion of working hours. In Situation C, noise levels were >82 dB(A) around shovels. Noise levels on both sides of conveyor belts were in the range of 80–85 dB(A) in Situations A and C whereas it was 85–90 dB(A) in Situation B. Near crusher plants, it ranged from 80 to 90 dB(A) in Situations A and C and between 85 and 95 dB(A) in Situation B. In all situations, noise levels near residential areas exceeded the Central Pollution Control Board (CPCB) limits, i.e., 55 dB(A). Conclusions: For all situations, predicted noise levels exceeded CPCB limits within the mine and nearby residential area. Residential areas near the crusher plants are vulnerable to increased noise propagation. It is recommended to put an acoustic barrier near the crusher plant to attenuate the noise propagation. PMID:27569406

  6. An Updated Catalog of 521 Social Surveys of Residents' Reactions to Environmental Noise (1943-2000)

    NASA Technical Reports Server (NTRS)

    Fields, James M.; Shepherd, Kevin P. (Technical Monitor)

    2001-01-01

    This report describes all social surveys of residents' reactions to environmental noise in residential areas that have been located in English language publications from 1943 to December of 2000. A total of 521 surveys are described. The surveys are indexed by country, noise source, and date of survey. The publications and reports from each survey are listed in a bibliography.

  7. A catalog of social surveys of residents' reactions to environmental noise, 1943 - 1980

    NASA Technical Reports Server (NTRS)

    Fields, J. M.

    1981-01-01

    Two hundred social surveys of people's responses to environmental noise in residential areas are briefly described. The surveys are indexed by country, noise source and date of survey. The publications and reports about each survey are listed in a bibliography. Recent English translations of 14 publications are listed separately. Nineteen surveys are listed which are available for secondary analysis from a data archive.

  8. Sleep Disturbance from Road Traffic, Railways, Airplanes and from Total Environmental Noise Levels in Montreal

    PubMed Central

    Perron, Stéphane; Plante, Céline; Ragettli, Martina S.; Kaiser, David J.; Goudreau, Sophie; Smargiassi, Audrey

    2016-01-01

    The objective of our study was to measure the impact of transportation-related noise and total environmental noise on sleep disturbance for the residents of Montreal, Canada. A telephone-based survey on noise-related sleep disturbance among 4336 persons aged 18 years and over was conducted. LNight for each study participant was estimated using a land use regression (LUR) model. Distance of the respondent’s residence to the nearest transportation noise source was also used as an indicator of noise exposure. The proportion of the population whose sleep was disturbed by outdoor environmental noise in the past 4 weeks was 12.4%. The proportion of those affected by road traffic, airplane and railway noise was 4.2%, 1.5% and 1.1%, respectively. We observed an increased prevalence in sleep disturbance for those exposed to both rail and road noise when compared for those exposed to road only. We did not observe an increased prevalence in sleep disturbance for those that were both exposed to road and planes when compared to those exposed to road or planes only. We developed regression models to assess the marginal proportion of sleep disturbance as a function of estimated LNight and distance to transportation noise sources. In our models, sleep disturbance increased with proximity to transportation noise sources (railway, airplane and road traffic) and with increasing LNight values. Our study provides a quantitative estimate of the association between total environmental noise levels estimated using an LUR model and sleep disturbance from transportation noise. PMID:27529260

  9. Error Sensitivity to Environmental Noise in Quantum Circuits for Chemical State Preparation.

    PubMed

    Sawaya, Nicolas P D; Smelyanskiy, Mikhail; McClean, Jarrod R; Aspuru-Guzik, Alán

    2016-07-12

    Calculating molecular energies is likely to be one of the first useful applications to achieve quantum supremacy, performing faster on a quantum than a classical computer. However, if future quantum devices are to produce accurate calculations, errors due to environmental noise and algorithmic approximations need to be characterized and reduced. In this study, we use the high performance qHiPSTER software to investigate the effects of environmental noise on the preparation of quantum chemistry states. We simulated 18 16-qubit quantum circuits under environmental noise, each corresponding to a unitary coupled cluster state preparation of a different molecule or molecular configuration. Additionally, we analyze the nature of simple gate errors in noise-free circuits of up to 40 qubits. We find that, in most cases, the Jordan-Wigner (JW) encoding produces smaller errors under a noisy environment as compared to the Bravyi-Kitaev (BK) encoding. For the JW encoding, pure dephasing noise is shown to produce substantially smaller errors than pure relaxation noise of the same magnitude. We report error trends in both molecular energy and electron particle number within a unitary coupled cluster state preparation scheme, against changes in nuclear charge, bond length, number of electrons, noise types, and noise magnitude. These trends may prove to be useful in making algorithmic and hardware-related choices for quantum simulation of molecular energies.

  10. Considering the influence of artificial environmental noise to study cough time-frequency features

    NASA Astrophysics Data System (ADS)

    Van Hirtum, A.; Berckmans, D.

    2003-09-01

    In general the study of the cough mechanism and sound in both animal and human is performed by eliciting coughing in a reproducible way by nebulization of an irritating substance. Due to ventilation the controlled evaporation-protocol causes artificial noises from a mechanical origin. The resulting environmental low-frequency noises complicate cough time-frequency features. In order to optimize the study of the cough-sound the research described in this paper attempts on the one hand to characterize and model the environmental noises and on the other hand to evaluate the influence of the noise on the time-frequency representation for the intended cough sounds by comparing different de-noising approaches. Free field acoustic sound is continuously registered during 30 min citric acid cough-challenges on individual Belgian Landrace piglets and during respiratory infection experiments, with a duration of about 10 days, where room-ventilation was present.

  11. Involuntary and Persistent Environmental Noise Influences Health and Hearing in Beirut, Lebanon

    PubMed Central

    Fooladi, Marjaneh M.

    2012-01-01

    Objective. This study was conducted to assess the effects of involuntary and persistent noise exposure on health and hearing among Lebanese adults in Beirut, Lebanon, where people are exposed to noise from construction sites, power generators, honking cars, and motorcycles. Methods. Using a descriptive and exploratory design with mixed methods, participants were surveyed, interviewed, and tested for hearing while street noise levels were measured near their residents and work places. Results. Self-reports of 83 Lebanese adult, who lived and worked in Beirut, helped identify common patterns in experiences such as irritability, anger, headaches, and sleep disturbances due to noise annoyance. Of those tested, 30% suffered from high-frequency hearing impairment. Our results showed that environmental sound dB had increased by 12% and sound intensity by 400% above the maximum standard level when compared to the WHO report of 1999. Conclusion. Environmental noise contributes to premature hearing loss and potentiates systemic diseases among Lebanese. PMID:22013454

  12. Active self-testing noise measurement sensors for large-scale environmental sensor networks.

    PubMed

    Domínguez, Federico; Cuong, Nguyen The; Reinoso, Felipe; Touhafi, Abdellah; Steenhaut, Kris

    2013-12-13

    Large-scale noise pollution sensor networks consist of hundreds of spatially distributed microphones that measure environmental noise. These networks provide historical and real-time environmental data to citizens and decision makers and are therefore a key technology to steer environmental policy. However, the high cost of certified environmental microphone sensors render large-scale environmental networks prohibitively expensive. Several environmental network projects have started using off-the-shelf low-cost microphone sensors to reduce their costs, but these sensors have higher failure rates and produce lower quality data. To offset this disadvantage, we developed a low-cost noise sensor that actively checks its condition and indirectly the integrity of the data it produces. The main design concept is to embed a 13 mm speaker in the noise sensor casing and, by regularly scheduling a frequency sweep, estimate the evolution of the microphone's frequency response over time. This paper presents our noise sensor's hardware and software design together with the results of a test deployment in a large-scale environmental network in Belgium. Our middle-range-value sensor (around €50) effectively detected all experienced malfunctions, in laboratory tests and outdoor deployments, with a few false positives. Future improvements could further lower the cost of our sensor below €10.

  13. Active Self-Testing Noise Measurement Sensors for Large-Scale Environmental Sensor Networks

    PubMed Central

    Domínguez, Federico; Cuong, Nguyen The; Reinoso, Felipe; Touhafi, Abdellah; Steenhaut, Kris

    2013-01-01

    Large-scale noise pollution sensor networks consist of hundreds of spatially distributed microphones that measure environmental noise. These networks provide historical and real-time environmental data to citizens and decision makers and are therefore a key technology to steer environmental policy. However, the high cost of certified environmental microphone sensors render large-scale environmental networks prohibitively expensive. Several environmental network projects have started using off-the-shelf low-cost microphone sensors to reduce their costs, but these sensors have higher failure rates and produce lower quality data. To offset this disadvantage, we developed a low-cost noise sensor that actively checks its condition and indirectly the integrity of the data it produces. The main design concept is to embed a 13 mm speaker in the noise sensor casing and, by regularly scheduling a frequency sweep, estimate the evolution of the microphone's frequency response over time. This paper presents our noise sensor's hardware and software design together with the results of a test deployment in a large-scale environmental network in Belgium. Our middle-range-value sensor (around €50) effectively detected all experienced malfunctions, in laboratory tests and outdoor deployments, with a few false positives. Future improvements could further lower the cost of our sensor below €10. PMID:24351634

  14. Detecting drawdowns masked by environmental stresses with water-level models

    USGS Publications Warehouse

    Garcia, C.A.; Halford, K.J.; Fenelon, J.M.

    2013-01-01

    Detecting and quantifying small drawdown at observation wells distant from the pumping well greatly expands the characterized aquifer volume. However, this detection is often obscured by water level fluctuations such as barometric and tidal effects. A reliable analytical approach for distinguishing drawdown from nonpumping water-level fluctuations is presented and tested here. Drawdown is distinguished by analytically simulating all pumping and nonpumping water-level stresses simultaneously during the period of record. Pumping signals are generated with Theis models, where the pumping schedule is translated into water-level change with the Theis solution. This approach closely matched drawdowns simulated with a complex three-dimensional, hypothetical model and reasonably estimated drawdowns from an aquifer test conducted in a complex hydrogeologic system. Pumping-induced changes generated with a numerical model and analytical Theis model agreed (RMS as low as 0.007 m) in cases where pumping signals traveled more than 1 km across confining units and fault structures. Maximum drawdowns of about 0.05 m were analytically estimated from field investigations where environmental fluctuations approached 0.2 m during the analysis period.

  15. Detecting Drawdowns Masked by Environmental Stresses with Water-Level Models

    PubMed Central

    Garcia, CA; Halford, KJ; Fenelon, JM

    2013-01-01

    Detecting and quantifying small drawdown at observation wells distant from the pumping well greatly expands the characterized aquifer volume. However, this detection is often obscured by water level fluctuations such as barometric and tidal effects. A reliable analytical approach for distinguishing drawdown from nonpumping water-level fluctuations is presented and tested here. Drawdown is distinguished by analytically simulating all pumping and nonpumping water-level stresses simultaneously during the period of record. Pumping signals are generated with Theis models, where the pumping schedule is translated into water-level change with the Theis solution. This approach closely matched drawdowns simulated with a complex three-dimensional, hypothetical model and reasonably estimated drawdowns from an aquifer test conducted in a complex hydrogeologic system. Pumping-induced changes generated with a numerical model and analytical Theis model agreed (RMS as low as 0.007 m) in cases where pumping signals traveled more than 1 km across confining units and fault structures. Maximum drawdowns of about 0.05 m were analytically estimated from field investigations where environmental fluctuations approached 0.2 m during the analysis period. PMID:23469925

  16. The effects of environmental and classroom noise on the academic attainments of primary school children.

    PubMed

    Shield, Bridget M; Dockrell, Julie E

    2008-01-01

    While at school children are exposed to various types of noise including external, environmental noise and noise generated within the classroom. Previous research has shown that noise has detrimental effects upon children's performance at school, including reduced memory, motivation, and reading ability. In England and Wales, children's academic performance is assessed using standardized tests of literacy, mathematics, and science. A study has been conducted to examine the impact, if any, of chronic exposure to external and internal noise on the test results of children aged 7 and 11 in London (UK) primary schools. External noise was found to have a significant negative impact upon performance, the effect being greater for the older children. The analysis suggested that children are particularly affected by the noise of individual external events. Test scores were also affected by internal classroom noise, background levels being significantly related to test results. Negative relationships between performance and noise levels were maintained when the data were corrected for socio-economic factors relating to social deprivation, language, and special educational needs. Linear regression analysis has been used to estimate the maximum levels of external and internal noise which allow the schools surveyed to achieve required standards of literacy and numeracy.

  17. Research on noise and vibration reduction at DB to improve the environmental friendliness of railway traffic

    NASA Astrophysics Data System (ADS)

    Schulte-Werning, B.; Beier, M.; Degen, K. G.; Stiebel, D.

    2006-06-01

    One of the most prominent keywords relating to the environmental friendliness of railway traffic is noise reduction. Thus, the research and development programme "Low Noise Railway" of Deutsche Bahn (DB) is under way to treat the noise of the vehicles and infrastructure. The noise reduction of the trains and the rail/wheel system are being tackled within several projects. The direct noise experienced by railway-lineside residents due to train movements on the track can be reduced by minimising the sound radiation directly at the source. This is the first-choice solution, as it proves to be the most effective countermeasure regarding a cost-benefit relation. The limit values for the noise emission as specified in the technical specification for interoperability are an essential criterion to be confirmed during the procurement process of railway vehicles. A recently developed acoustical quality management scheme establishes systematic noise management to complete the vehicle procurement process in the phases of concept, design, construction and manufacturing. In freight traffic quiet railway wheels for block brake operation will play an important role in the future to meet the goal of a low-noise railway system. A first attempt to realise successfully the low-noise potential of such optimised wheels was performed, even if with mixed results. To show ways of reducing the noise of the cooling ventilation in locomotives, DB is a partner in a development project led by Siemens. A notable 8 dB(A) noise reduction was measured. Concerning bridge noise, a project was started based on an effective and cost-efficient combination of experiments and simulations in order to develop specifications for the construction of generic low-noise bridges.

  18. Environmental noise levels affect the activity budget of the Florida manatee

    NASA Astrophysics Data System (ADS)

    Miksis-Olds, Jennifer L.; Donaghay, Percy L.; Miller, James H.; Tyack, Peter L.

    2005-09-01

    Manatees inhabit coastal bays, lagoons, and estuaries because they are dependent on the aquatic vegetation that grows in shallow waters. Food requirements force manatees to occupy the same areas in which human activities are the greatest. Noise produced from human activities has the potential to affect these animals by eliciting responses ranging from mild behavioral changes to extreme aversion. This study quantifies the behavioral responses of manatees to both changing levels of ambient noise and transient noise sources. Results indicate that elevated environmental noise levels do affect the overall activity budget of this species. The proportion of time manatees spend feeding, milling, and traveling in critical habitats changed as a function of noise level. More time was spent in the directed, goal-oriented behaviors of feeding and traveling, while less time was spent milling when noise levels were highest. The animals also responded to the transient noise of approaching vessels with changes in behavioral state and movements out of the geographical area. This suggests that manatees detect and respond to changes in environmental noise levels. Whether these changes legally constitute harassment and produce biologically significant effects need to be addressed with hypothesis-driven experiments and long-term monitoring. [For Animal Bioacoustics Best Student Paper Award.

  19. A vision of the environmental and occupational noise pollution in Malaysia.

    PubMed

    Yuen, Foo Keng

    2014-01-01

    Environmental noise remains a complex and fragmented interplay between industrialization, population growth, technological developments, and the living environment. Next to the circulatory diseases and cancer, noise pollution has been cited as the third epidemic cause of psychological and physiological disorders internationally. A reliable and firm relationship between the cumulative health implications with the traffic annoyance and occupational noise has been established. This agenda has called for an integrated, coordinated, and participatory approach to the reliable protection of noise interference. Despite several fragmented policies, legislation and global efforts have been addressed; the noise pollution complaints have been traditionally neglected in developing countries, especially in Malaysia. This paper was undertaken to postulate an initial platform to address the dynamic pressures, gigantic challenges, and tremendous impacts of noise pollution scenario in Malaysia. The emphasis is speculated on the traffic interference and assessment of industrial and occupational noise. The fundamental importance of noise monitoring and modeling is proposed. Additionally, the confronting conservation program and control measure for noise pollution control are laconically elucidated.

  20. The influence of preconceptions on perceived sound reduction by environmental noise barriers.

    PubMed

    Joynt, Jennifer L R; Kang, Jian

    2010-09-15

    The paper presents research that answers three main questions: (1) Do preconceptions held about the constituent materials of an environmental noise barrier affect how people perceive the barrier will perform at attenuating noise? (2) Does aesthetic preference influence the perception of how a barrier will perform? (3) Are barriers, which are deemed more aesthetically pleasing, more likely to be perceived as better noise attenuators? In a virtual reality setting with film to improve the contextual realism of the intersensory interaction test, participants were required to compare the perceived effectiveness of five standard 'in-situ' noise barriers, including concrete, timber, metal, transparent acrylic and a vegetative screen. The audio stimulus was held at a constant sound pressure level (SPL), whilst the visual stimulus changed, as the influential factor. As the noise levels projected during the study were held constant, it was possible to attribute the participants' perception of noise attenuation by the barriers, to preconceptions of how the varying barrier material would attenuate noise. There was also an inverse correlation between aesthetics and perception of how a noise barrier would perform. The transparent and deciduous vegetation barriers, judged most aesthetically pleasing, were judged as the least effective at attenuating noise.

  1. An updated catalog of 318 social surveys of residents' reactions to environmental noise (1943-1989)

    NASA Technical Reports Server (NTRS)

    Fields, James M.

    1991-01-01

    All social surveys of residents' reactions to environmental noise in residential areas which were described in English language publications from 1943 to 1989 are identified. A total of 318 surveys are described. The surveys are indexed by country, noise source, and data of survey. The publications and reports from each survey are listed in a bibliography. Twenty-four surveys are listed which are available for secondary analysis from a data archive.

  2. Plant reproduction and environmental noise: how do plants do it?

    PubMed

    Lyles, Danielle; Rosenstock, Todd S; Hastings, Alan

    2015-04-21

    Plant populations exhibit a wide continuum of reproductive behavior, ranging from nearly constant reproductive output on one end to the extreme of masting (synchronized, highly variable reproduction) on the other. Here, we show that including variability (noise) in density-dependent pollen limitation in current models for pollen-limited plant reproduction may produce any behavior on this continuum. We previously showed that (large) variability in pollination efficiency (a related phenomenon) may induce masting in non-pollen-limited plant populations. Other modeling studies have shown that including variability in accumulated resources (and/or the threshold for reproduction) may induce masting, but do account for masting in non-pollen-limited plant populations. Thus, our results suggest that the range of plant reproductive behavior may be explained with the simple resource budget model combined with the biological realism of variability in density-dependent pollen limitation. This is a specific example of an important functional consequence of the interactions between stochasticity and nonlinearity, and highlights the importance of carefully considering both the biological basis and the mathematical effects of the noise term.

  3. Immersive virtual reality and environmental noise assessment: An innovative audio–visual approach

    SciTech Connect

    Ruotolo, Francesco; Maffei, Luigi; Di Gabriele, Maria; Iachini, Tina; Masullo, Massimiliano; Ruggiero, Gennaro; Senese, Vincenzo Paolo

    2013-07-15

    Several international studies have shown that traffic noise has a negative impact on people's health and that people's annoyance does not depend only on noise energetic levels, but rather on multi-perceptual factors. The combination of virtual reality technology and audio rendering techniques allow us to experiment a new approach for environmental noise assessment that can help to investigate in advance the potential negative effects of noise associated with a specific project and that in turn can help designers to make educated decisions. In the present study, the audio–visual impact of a new motorway project on people has been assessed by means of immersive virtual reality technology. In particular, participants were exposed to 3D reconstructions of an actual landscape without the projected motorway (ante operam condition), and of the same landscape with the projected motorway (post operam condition). Furthermore, individuals' reactions to noise were assessed by means of objective cognitive measures (short term verbal memory and executive functions) and subjective evaluations (noise and visual annoyance). Overall, the results showed that the introduction of a projected motorway in the environment can have immediate detrimental effects of people's well-being depending on the distance from the noise source. In particular, noise due to the new infrastructure seems to exert a negative influence on short term verbal memory and to increase both visual and noise annoyance. The theoretical and practical implications of these findings are discussed. -- Highlights: ► Impact of traffic noise on people's well-being depends on multi-perceptual factors. ► A multisensory virtual reality technology is used to simulate a projected motorway. ► Effects on short-term memory and auditory and visual subjective annoyance were found. ► The closer the distance from the motorway the stronger was the effect. ► Multisensory virtual reality methodologies can be used to study

  4. Spatial variation in environmental noise and air pollution in New York City.

    PubMed

    Kheirbek, Iyad; Ito, Kazuhiko; Neitzel, Richard; Kim, Jung; Johnson, Sarah; Ross, Zev; Eisl, Holger; Matte, Thomas

    2014-06-01

    Exposure to environmental noise from traffic is common in urban areas and has been linked to increased risks of adverse health effects including cardiovascular disease. Because traffic sources also produce air pollutants that increase the risk of cardiovascular morbidity, associations between traffic exposures and health outcomes may involve confounding and/or synergisms between air pollution and noise. While prior studies have characterized intraurban spatial variation in air pollution in New York City (NYC), limited data exists on the levels and spatial variation in noise levels. We measured 1-week equivalent continuous sound pressure levels (Leq) at 56 sites during the fall of 2012 across NYC locations with varying traffic intensity and building density that are routinely monitored for combustion-related air pollutants. We evaluated correlations among several noise metrics used to characterize noise exposures, including Leq during different time periods (night, day, weekday, weekend), Ldn (day-night noise), and measures of intermittent noise defined as the ratio of peak levels to median and background levels. We also examined correlations between sound pressure levels and co-located simultaneous measures of nitric oxide (NO), nitrogen dioxide (NO2), fine particulate matter (PM2.5), and black carbon (BC) as well as estimates of traffic and building density around the monitoring sites. Noise levels varied widely across the 56 monitoring sites; 1-week Leq varied by 21.6 dBA (range 59.1-80.7 dBA) with the highest levels observed during the weekday, daytime hours. Indices of average noise were well correlated with each other (r > 0.83), while indices of intermittent noise were not well correlated with average noise levels (r < 0.41). One-week Leq correlated well with NO, NO2, and EC levels (r = 0.61 to 0.68) and less so with PM2.5 levels (r = 0.45). We observed associations between 1-week noise levels and traffic intensity within 100 m of the monitoring sites (r = 0

  5. Benefits and disadvantages of self-regulation of environmental noise from military training

    NASA Astrophysics Data System (ADS)

    Luz, George A.

    2002-05-01

    In a 1981 Executive decision, the Administration's Office of Management and Budget (OMB) told the Environmental Protection Agency to end funding of the Office of Noise Abatement and Control (ONAC). This decision, coupled with a specific exemption for military equipment contained in the Noise Control Act of 1972, ensured that the military departments would be self-regulating in regard to noise. This self-regulation for noise stands in contrast to the external regulation of other pollutants, such as air and water emissions. Two possible disadvantages of self-regulation are (1) reduced funding for noise management compared with funding for externally regulated pollutants, and (2) lack of an independent and external set of standards for determining acceptable limits on community noise exposure. Three possible benefits are (1) avoiding the costs of mitigating trivial violations of external standards, (2) maintaining a long-standing policy of preventing noise problems through land use planning, and (3) enabling negotiated solutions between installations and their neighboring communities. The paper ends with an examination of a negotiated solution for a community subjected to noise from the detonation of obsolete ammunition.

  6. Aircraft Noise Perception Study in Brazil: A Perspective on Airport Sustainable Growth and Environmental Awareness

    NASA Technical Reports Server (NTRS)

    deArantesGomesEller, Rogerio; Urbina, Ligia Maria Soto; Porto, Protogenes Pires

    2003-01-01

    Aircraft noise perception is related to several variables that are tangible and objective, such as the number of operations, flight schedules. Other variables, instead, are more subjective, such as preferences. However, although their elusiveness, they contribute to determine the individuals' perception of this type of externality. Despite the fact that the complaints related to aeronautical noise have been registered since the decade of 50, it has been observed that the perception of noise seems to have grown, especially since the 80's. It has been argued that this change in noise perception has its roots on the accelerated expansion of air traffic. But, it is necessary to point out the important role played on modeling preferences, by the growing environmental conscience and the higher welfare and quality of life standards and expectations. In that context, the main objective of this paper is to study the aeronautical noise perception in the neighborhoods of the Aeroporto Internacional de Sao Paulo - AISP (the biggest airport of South America). Specifically, it analyzes the relationship between aircraft noise perception and social class, which is expected to be positive. Since noise perception is an intangible variable, this study chose as a proxy the value losses of residential properties, caused by aeronautical noise. The variable social class has been measured utilizing average per capita income of the population who live nearby the airport. The comparison of both, the lowest and the highest social class suggests that the relationship between social class and noise perception is positive in the AISP region. Moreover, it was observed that all social classes are very susceptible to aircraft noise annoyance. In fact, the magnitude of the noise perception proxy for both social classes -the residential value losses- was found to be comparable to levels encountered in developed countries.

  7. Environmental noise from the Naesudden (Sweden) and Maglarp (Sweden) prototype wind turbines: A study of machinery noise

    NASA Astrophysics Data System (ADS)

    Ljunggren, Sten; Johansson, Melker; Sahlin, Per

    1990-08-01

    The noise generated by the machinery of the two prototypes contains pure tones, which are very important with respect to the environmental impact. The gearbox is shown to be the most important source in both units. It is also shown that a predominant part of the noise is transmitted as structure borne sound from the source to the radiating parts of the structure in the Naesudden unit and as airborne sound in the Maglarp case. The transmission depends heavily on the load bearing properties of the power line. Thus, the noise level around the Naesudden turbine is significantly higher due to its monocoque design than the level of the Maglarp unit where a separate frame is used. Add on measures to reduce this transmission are not easily found as the gearbox acts as a velocity source. The measurements at the Naesudden turbine also show that the radiation from the load bearing hub and the steel blades may be important beside that from the nacelle. The results from Maglarp show in a similar way that the radiation from a steel tower must not be neglected.

  8. Explaining "Noise" as Environmental Variations in Population Dynamics

    SciTech Connect

    Ginn, Timothy R.; Loge, Frank J.; Scheibe, Timothy D.

    2007-03-01

    The impacts of human activities on our own and other populations on the plant are making news at an alarming pace. Global warming, ocean and freshwater contamination and acidification, deforestation, habitat destruction and incursion, and in general a burgeoning human population are associated with a complete spectrum of changes to the dynamics of populations. Effects on songbirds, insects, coral reefs, ocean mammals, anadromous fishes, just to name a few, and humans, have been linked to human industry and population growth. The linkage, however, remains often ghostly and often tenuous at best, because of the difficulty in quantitatively combining ecological processes with environmental fate and transport processes. Establishing quantitative tools, that is, models, for the combined dynamics of populations and environmental chemical/thermal things is needed. This truly interdisciplinary challenge is briefly reviewed, and two approaches to integrating chemical and biological intermingling are addressed in the context of salmon populations in the Pacific Northwest.

  9. From environmental noise abatement to soundscape creation through strategic noise mapping in medium urban agglomerations in South Europe.

    PubMed

    Vogiatzis, Konstantinos; Remy, Nicolas

    2014-06-01

    In the framework of the European Directive 2002-49-EU, the medium sized cities of Volos and Larissa in central Greece recently completed (2012) their strategic noise maps and relevant action plans that define the main strategies to reduce noise exposure of residents and introduce and preserve "quite zones". For the first time in this framework, it has been decided to introduce, as well, a general study for five specific urban districts covering not only the measurement and modeling of environmental noise levels but also qualitative surveys on the sound perception by the residents and several analyses of the urban and architectural tissue. The districts (respectively four in Volos and one in Larissa with the two of them in the center of both agglomerations) were chosen as representatives of urban situations due to their proximity to transportation infrastructures (main road network, industrial harbor facilities and both regional and intercity train network) and also because they represent different urban typologies (residential district, downtown area with or without shops, more or less densely populated neighborhood, etc.…). Sociological surveys on sound and noise perception have been implemented on some 15% of the residents per district using opened questionnaires. Soundscape analysis was also conducted through qualitative criteria. A cross-analysis of these data explains in detail the physical reasons for the existence of sound qualities that contribute to the identity of each distinct neighborhood. This paper, in a strategic plan level, has introduced valuable recommendations in order not only to preserve the sound quality on the existing sites but also to authorize developers and decision makers (mayors, architects, town planners) to evolve them positively over time.

  10. Environmental noise-exposed workers: event-related potentials, neuropsychological and mood assessment.

    PubMed

    Chiovenda, Paola; Pasqualetti, Patrizio; Zappasodi, Filippo; Ercolani, Matilde; Milazzo, Daniele; Tomei, Gianfranco; Capozzella, Assuntina; Tomei, Francesco; Rossini, Paolo M; Tecchio, Franca

    2007-09-01

    Prolonged environmental noise exposure can induce pathogenic effects on various physical and psychosocial responses. The first aim of this study was to investigate whether long-term occupational noise exposure could affect neurophysiological, neuropsychological and emotional statuses, with particular respect to attention and working memory. The second aim was to evaluate the effects on the tactile P300 of a specific stressor (background traffic noise) vs a non-specific stress inductor (Stroop test). The comparison between a group of noise-exposed workers (traffic police officers), and a control group (office employees) did not show marked differences in cognitive and emotional profiles. The amplitude of the baseline cognitive potential (P300), recorded during a tactile (electric) discrimination task, resulted higher in noise-exposed workers than in controls, and this enhancement was associated with a lower level of trait anxiety and better mood profiles. Moreover, we found a wider P300 amplitude reduction in traffic police officers than in controls, under noisy conditions due to traffic. The effect of the Stroop test as a stress inductor was negligible and similar in the two groups. The wider amplitude of the non-auditory P300 in traffic police officers in the baseline condition could be a sign of cross-modal cerebral plasticity enhancing attentive processes in the 'stress-free' sensory channel. In addition, noise-exposed workers presented a higher cerebral sensitivity to stress selectively when they were exposed to the habitual environmental stressor.

  11. Determination and Applications of Environmental Costs at Different Sized Airports: Aircraft Noise and Engine Emissions

    NASA Technical Reports Server (NTRS)

    Lu, Cherie; Lierens, Abigail

    2003-01-01

    With the increasing trend of charging for externalities and the aim of encouraging the sustainable development of the air transport industry, there is a need to evaluate the social costs of these undesirable side effects, mainly aircraft noise and engine emissions, for different airports. The aircraft noise and engine emissions social costs are calculated in monetary terms for five different airports, ranging from hub airports to small regional airports. The number of residences within different levels of airport noise contours and the aircraft noise classifications are the main determinants for accessing aircraft noise social costs. Whist, based on the damages of different engine pollutants on the human health, vegetation, materials, aquatic ecosystem and climate, the aircraft engine emissions social costs vary from engine types to aircraft categories. The results indicate that the relationship appears to be curvilinear between environmental costs and the traffic volume of an airport. The results and methodology of environmental cost calculation could input for to the proposed European wide harmonized noise charges as well as the social cost benefit analysis of airports.

  12. Computer analysis of environmental temperature, light and noise in intensive care: chaos or chronome nurseries?

    PubMed

    Ardura, J; Andrés, J; Aldana, J; Revilla, M A; Cornélissen, G; Halberg, F

    1997-09-01

    Lighting, noise and temperature were monitored in two perinatal nurseries. Rhythms of several frequencies were found, including prominent 24-hour rhythms with acrophases around 13:00 (light intensity) and 16:00 (noise). For light and noise, the ratio formed by dividing the amplitude of a 1-week (circaseptan) or half-week (circasemiseptan) fitted cosine curve by the amplitude of a 24-hour fitted cosine curve is smaller than unity, since 24-hour rhythms are prominent for these variables. The amplitude ratios are larger than unity for temperature in the newborns' unit but not in the infants' unit. Earlier, the origin of the about-7-day rhythms of neonatal physiologic variables was demonstrated to have, in addition to a major endogenous, also a minor exogenous component. Hence, the possibility of optimizing maturation by manipulating environmental changes can be considered, using, as gauges of development, previously mapped chronomes (time structures of biologic multifrequency rhythms, trends and noise).

  13. Environmental noise and annoyance in adult population of Skopje: a cross-sectional study.

    PubMed

    Ristovska, Gordana; Gjorgjev, Dragan; Polozhani, Aziz; Kocubovski, Mihail; Kendrovski, Vladimir

    2009-09-01

    The aim of this study was to identify noise exposure indicators during day and night in the city of Skopje and to see if there is an association between these noise exposure indicators and annoyance. We have performed noise measurements and interviewed 510 adult subjects, using a questionnaire, prepared according to the ISO/TS-15666 standard. Average noise level over the day (Lday) was (62+/-6.45) dB(A) and over night (Lnight) (56+/-6.52) dB(A). Thirteen percent of subjects reported a high level, and 33.5% moderate level of annoyance. The most annoying noise sources were construction activities (34% of the subjects), road traffic (24%), and leisure/entertainment activities (18%). We found a significant association between exposure to Lday in the range 61 dB(A) to 65 dB(A) and annoyance in the exposed population (chi-square = 86.14; p<0.001; Spearman's R=0.45; p<0.05). During the night time annoyance was reported with exposure to Lnight above 46 dB(A). Levels of annoyance in Macedonia are similar to levels in developed European countries. Differences are in the source of noise. This study has shown that environmental noise is a significant hazard in urban environments, and assessment of annoyance may prove a useful tool for town planners and public health policy makers.

  14. Combined acoustical and visual performance of noise barriers in mitigating the environmental impact of motorways.

    PubMed

    Jiang, Like; Kang, Jian

    2016-02-01

    This study investigated the overall performance of noise barriers in mitigating environmental impact of motorways, taking into consideration their effects on reducing noise and visual intrusions of moving traffic, but also potentially inducing visual impact themselves. A laboratory experiment was carried out, using computer-visualised video scenes and motorway traffic noise recordings to present experimental scenarios covering two traffic levels, two distances of receiver to road, two types of background landscape, and five barrier conditions including motorway only, motorway with tree belt, motorways with 3 m timber barrier, 5m timber barrier, and 5m transparent barrier. Responses from 30 participants of university students were gathered and perceived barrier performance analysed. The results show that noise barriers were always beneficial in mitigating environmental impact of motorways, or made no significant changes in environmental quality when the impact of motorways was low. Overall, barriers only offered similar mitigation effect as compared to tree belt, but showed some potential to be more advantageous when traffic level went high. 5m timber barrier tended to perform better than the 3m one at the distance of 300 m but not at 100 m possibly due to its negative visual effect when getting closer. The transparent barrier did not perform much differently from the timber barriers but tended to be the least effective in most scenarios. Some low positive correlations were found between aesthetic preference for barriers and environmental impact reduction by the barriers.

  15. Graduate Student Learning Styles and the Environmental Factor of Noise: A Pilot Study.

    ERIC Educational Resources Information Center

    van der Jagt, Johan W.; Anzelmo-Skelton, Nicki; Madison, Marion; Gum, Louann

    This study investigated the relationships among environmental noise (i.e., location, type, and constancy) and graduate student preferred learning styles (visual-overhead transparencies, auditory-lecture, kinesthetic-activity), gender, and age differences. The participants were 43 graduate students, who were currently teachers with experience…

  16. Influences of environmental noise level and respiration rate on the accuracy of acoustic respiration rate monitoring.

    PubMed

    Yabuki, Shizuha; Toyama, Hiroaki; Takei, Yusuke; Wagatsuma, Toshihiro; Yabuki, Hiroshi; Yamauchi, Masanori

    2017-02-07

    We tested the hypothesis that the environmental noise generated by a forced-air warming system reduces the monitoring accuracy of acoustic respiration rate (RRa). Noise levels were adjusted to 45-55, 56-65, 66-75, and 76-85 dB. Healthy participants breathed at set respiration rates (RRset) of 6, 12, and 30/min. Under each noise level at each RRset, the respiration rates by manual counting (RRm) and RRa were recorded. Any appearance of the alarm display on the RRa monitor was also recorded. Each RRm of all participants agreed with each RRset at each noise level. At 45-55 dB noise, the RRa of 13, 17, and 17 participants agreed with RRset of 6, 12, and 30/min, respectively. The RRa of 14, 17, and 16 participants at 56-65 dB noise, agreed with RRset of 6, 12, and 30/min, respectively. At 66-75 dB noise, the RRa of 9, 15, and 16 participants agreed with RRset of 6, 12, and 30/min, respectively. The RRa of one, nine, and nine participants at 76-85 dB noise agreed with RRset of 6, 12, and 30/min, respectively, which was significantly less than the other noise levels (P < 0.05). Overall, 72.9% of alarm displays highlighted incorrect values of RRa. In a noisy situation involving the operation of a forced-air warming system, the acoustic respiration monitoring should be used carefully especially in patients with a low respiration rate.

  17. Advances in the development of common noise assessment methods in Europe: The CNOSSOS-EU framework for strategic environmental noise mapping.

    PubMed

    Kephalopoulos, Stylianos; Paviotti, Marco; Anfosso-Lédée, Fabienne; Van Maercke, Dirk; Shilton, Simon; Jones, Nigel

    2014-06-01

    The Environmental Noise Directive (2002/49/EC) requires EU Member States to determine the exposure to environmental noise through strategic noise mapping and to elaborate action plans in order to reduce noise pollution, where necessary. A common framework for noise assessment methods (CNOSSOS-EU) has been developed by the European Commission in co-operation with the EU Member States to be applied for strategic noise mapping as required by the Environment Noise Directive (2002/49/EC). CNOSSOS-EU represents a harmonised and coherent approach to assess noise levels from the main sources of noise (road traffic, railway traffic, aircraft and industrial) across Europe. This paper outlines the process behind the development of CNOSSOS-EU and the parts of the CNOSSOS-EU core methodological framework which were developed during phase A of the CNOSSOS-EU process (2010-2012), whilst focusing on the main scientific and technical issues that were addressed, and the implementation challenges that are being faced before it can become fully operational in the EU MS.

  18. Variations in backward masking with different masking stimuli: II. The effects of spatially quantised masks in the light of local contour interaction, interchannel inhibition, perceptual retouch, and substitution theories.

    PubMed

    Bachmann, Talis; Luiga, Iiris; Põder, Endel

    2005-01-01

    In part I we showed that with spatially non-overlapping targets and masks both local metacontrast-like interactions and attentional processes are involved in backward masking. In this second part we extend the strategy of varying the contents of masks to pattern masking where targets and masks overlap in space, in order to compare different masking theories. Images of human faces were backward-masked by three types of spatially quantised masks (the same faces as targets, faces different from targets, and Gaussian noise with power spectra typical for faces). Configural characteristics, rather than the spectral content of the mask, predicted the extent of masking at relatively long stimulus onset asynchronies (SOAs). This poses difficulties for the theory of transient-on-sustained inhibition as the principal mechanism of masking and also for local contour interaction being a decisive factor in pattern masking. The scale of quantisation had no effect on the masking capacity of noise masks and a strong effect on the capacity of different-face masks. Also, the decrease of configural masking with an increase in the coarseness of the quantisation of the mask highlights ambiguities inherent in the re-entrance-based substitution theory of masking. Different masking theories cannot solve the problems of masking separately. They should be combined in order to create a complex, yet comprehensible mode of interaction for the different mechanisms involved in visual backward masking.

  19. Consideration of environmental noise effects in transportation planning by governmental entities

    NASA Technical Reports Server (NTRS)

    Mayo, L. H.

    1975-01-01

    Environmental concerns are reviewed with respect to major transportation systems: the interstate highway system and commercial air transportation. The type of planning that was done for interstate highway systems is described, and the shift in social value emphasis that has become apparent since the interstate system was authorized is considered. Other topics discussed include the constitutional framework for the allocation of governmental power with respect to transportation systems planning, governmental assessment of the aircraft noise problem, and evaluating the social benefit of noise abatement.

  20. Mask cost and specification

    NASA Astrophysics Data System (ADS)

    Watanabe, Hisashi; Higashikawa, Iwao

    2003-12-01

    At the panel discussion of Photomask Japan 2003, we discussed about Mask cost and specification. The topics are (1) Mask price trend and its impact, (2) How to reduce the mask costs; solutions from a mask shop, mask writing tool and mask inspection tool 3) Partnering mask suppliers with mask users; reasonable mask specification and OPC strategies. The choice of DUV laser writer instead of e-beam writer is one solution for reduction of mask cost. The continuous improvement of e-beam writer and resist sensitivity for high throughput is another solution. The partnership between designer, EDA vender, mask maker and wafer lithographer becomes more important.

  1. Masking effect of music upon oral information processing.

    PubMed

    Tsaneva, L

    2003-09-01

    The masking effect of three types of music and white masking noise upon special audiometric tests was determined in laboratory c. The stimulus-noise (S/N) ratio was found to be the most considerable factor influencing oral information processing in spite of the type of music or noise used as a masking agent. All types of music (modern, classic or modern music records in backwards order) showed no significant differences in masking being in the same way stronger maskers as white noise. Some conclusions are made concerning hygienic and ergonomic aspects of the problem.

  2. Sensitivity of coded mask telescopes

    SciTech Connect

    Skinner, Gerald K

    2008-05-20

    Simple formulas are often used to estimate the sensitivity of coded mask x-ray or gamma-ray telescopes, but these are strictly applicable only if a number of basic assumptions are met. Complications arise, for example, if a grid structure is used to support the mask elements, if the detector spatial resolution is not good enough to completely resolve all the detail in the shadow of the mask, or if any of a number of other simplifying conditions are not fulfilled. We derive more general expressions for the Poisson-noise-limited sensitivity of astronomical telescopes using the coded mask technique, noting explicitly in what circumstances they are applicable. The emphasis is on using nomenclature and techniques that result in simple and revealing results. Where no convenient expression is available a procedure is given that allows the calculation of the sensitivity. We consider certain aspects of the optimization of the design of a coded mask telescope and show that when the detector spatial resolution and the mask to detector separation are fixed, the best source location accuracy is obtained when the mask elements are equal in size to the detector pixels.

  3. Sensitivity of coded mask telescopes.

    PubMed

    Skinner, Gerald K

    2008-05-20

    Simple formulas are often used to estimate the sensitivity of coded mask x-ray or gamma-ray telescopes, but these are strictly applicable only if a number of basic assumptions are met. Complications arise, for example, if a grid structure is used to support the mask elements, if the detector spatial resolution is not good enough to completely resolve all the detail in the shadow of the mask, or if any of a number of other simplifying conditions are not fulfilled. We derive more general expressions for the Poisson-noise-limited sensitivity of astronomical telescopes using the coded mask technique, noting explicitly in what circumstances they are applicable. The emphasis is on using nomenclature and techniques that result in simple and revealing results. Where no convenient expression is available a procedure is given that allows the calculation of the sensitivity. We consider certain aspects of the optimization of the design of a coded mask telescope and show that when the detector spatial resolution and the mask to detector separation are fixed, the best source location accuracy is obtained when the mask elements are equal in size to the detector pixels.

  4. Communication masking in marine mammals: A review and research strategy.

    PubMed

    Erbe, Christine; Reichmuth, Colleen; Cunningham, Kane; Lucke, Klaus; Dooling, Robert

    2016-02-15

    Underwater noise, whether of natural or anthropogenic origin, has the ability to interfere with the way in which marine mammals receive acoustic signals (i.e., for communication, social interaction, foraging, navigation, etc.). This phenomenon, termed auditory masking, has been well studied in humans and terrestrial vertebrates (in particular birds), but less so in marine mammals. Anthropogenic underwater noise seems to be increasing in parts of the world's oceans and concerns about associated bioacoustic effects, including masking, are growing. In this article, we review our understanding of masking in marine mammals, summarise data on marine mammal hearing as they relate to masking (including audiograms, critical ratios, critical bandwidths, and auditory integration times), discuss masking release processes of receivers (including comodulation masking release and spatial release from masking) and anti-masking strategies of signalers (e.g. Lombard effect), and set a research framework for improved assessment of potential masking in marine mammals.

  5. Measurement and evaluation of the environmental noise levels in the urban areas of the city of Nis (Serbia).

    PubMed

    Prascevic, Momir R; Mihajlov, Darko I; Cvetkovic, Dragan S

    2014-02-01

    The environmental noise level represents one of the key factors of life quality in urban areas of modern cities. A continuous monitoring of the noise levels and the analysis of results have become a necessity when we discuss a possible recovery of those areas with high levels of noise pollution, and particularly, those zones which were designed for specific activities, e.g., areas around hospitals and schools. The city of Nis, Serbia, owing to the permanent long-term noise monitoring, possesses a database containing figures related to the noise levels at relevant locations in the city, which can serve as a basis for an analysis of the change of conditions, their tendencies in the future, and recognizing factors which influence the danger of noise pollution. The paper involves an analysis of the environmental noise level collected during the previous years.

  6. Clay Mask Workshop

    ERIC Educational Resources Information Center

    Gamble, David L.

    2012-01-01

    Masks can represent so many things, such as emotions (happy, sad, fearful) and power. The familiar "comedy and tragedy" masks, derived from ancient Greek theater, are just one example from mask history. Death masks from the ancient Egyptians influenced the ancient Romans into creating similar masks for their departed. Masks can represent many…

  7. NR2B subunit-dependent long-term potentiation enhancement in the rat cortical auditory system in vivo following masking of patterned auditory input by white noise exposure during early postnatal life.

    PubMed

    Hogsden, Jennifer L; Dringenberg, Hans C

    2009-08-01

    The composition of N-methyl-D-aspartate (NMDA) receptor subunits influences the degree of synaptic plasticity expressed during development and into adulthood. Here, we show that theta-burst stimulation of the medial geniculate nucleus reliably induced NMDA receptor-dependent long-term potentiation (LTP) of field postsynaptic potentials recorded in the primary auditory cortex (A1) of urethane-anesthetized rats. Furthermore, substantially greater levels of LTP were elicited in juvenile animals (30-37 days old; approximately 55% maximal potentiation) than in adult animals (approximately 30% potentiation). Masking patterned sound via continuous white noise exposure during early postnatal life (from postnatal day 5 to postnatal day 50-60) resulted in enhanced, juvenile-like levels of LTP (approximately 70% maximal potentiation) relative to age-matched controls reared in unaltered acoustic environments (approximately 30%). Rats reared in white noise and then placed in unaltered acoustic environments for 40-50 days showed levels of LTP comparable to those of adult controls, indicating that white noise rearing results in a form of developmental arrest that can be overcome by subsequent patterned sound exposure. We explored the mechanisms mediating white noise-induced plasticity enhancements by local NR2B subunit antagonist application in A1. NR2B subunit antagonists (Ro 25-6981 or ifenprodil) completely reversed white noise-induced LTP enhancement at concentrations that did not affect LTP in adult or age-matched controls. We conclude that white noise exposure during early postnatal life results in the maintenance of juvenile-like, higher levels of plasticity in A1, an effect that appears to be critically dependent on NR2B subunit activation.

  8. Evaluation of mobile smartphones app as a screening tool for environmental noise monitoring.

    PubMed

    Ibekwe, Titus S; Folorunsho, David O; Dahilo, Enoch A; Gbujie, Ibeneche O; Nwegbu, Maxwell M; Nwaorgu, Onyekwere G

    2016-01-01

    Noise is a global occupational and environmental health hazard with considerable social and physiological impact and, therefore, there is a need for regular measurements to boost monitoring and regulations of environmental noise levels in our communities. This necessitates a readily available, inexpensive, and easy to use noise measuring device. We aimed to test the sensitivity and validity of mobile "smart" phones for this purpose. This was a comparative analysis of a cross sectional study done between January 2014 and February 2015. Noise levels were measured simultaneously at different locations within Abuja Nigeria at day and night hours in real time environments. A sound level meter (SLM) (Extech407730 Digital Soundmeter, serial no.: 2310135, calibration no: 91037) and three smartphones (Samsung Galaxy note3, Nokia S, and Techno Phantom Z running on Android "Apps" Androidboy1) were used. Statistical calculations were done with Pearson correlation, T-test and Consistency within American National Standards Institute acceptable standard errors. Noise level readings for both daytime and night with the SLM and the mobile phones showed equivalent values. All noise level meters measured were <100dB. The daytime readings were nearly identical in six locations and the maximum difference in values between the SLM and Smartphone instruments was 3db, noted in two locations. Readings in dBA showed strong correlation (r = 0.9) within acceptable error limits for Type 2 SLM devices and no significant difference in the values (p = 0.12 & 0.58) for both day and night. Sensitivity of the instrument yielded 92.9%. The androidboy1 "app" performance in this study showed a good correlation and comparative high sensitivity to the Standard SLM (type 2 SLM device). However there is the need for further studies.

  9. Experience-dependent modulation of right anterior insula and sensorimotor regions as a function of noise-masked auditory feedback in singers and nonsingers.

    PubMed

    Kleber, Boris; Friberg, Anders; Zeitouni, Anthony; Zatorre, Robert

    2017-02-15

    Previous studies on vocal motor production in singing suggest that the right anterior insula (AI) plays a role in experience-dependent modulation of feedback integration. Specifically, when somatosensory input was reduced via anesthesia of the vocal fold mucosa, right AI activity was down regulated in trained singers. In the current fMRI study, we examined how masking of auditory feedback affects pitch-matching accuracy and corresponding brain activity in the same participants. We found that pitch-matching accuracy was unaffected by masking in trained singers yet declined in nonsingers. The corresponding brain region with the most differential and interesting activation pattern was the right AI, which was up regulated during masking in singers but down regulated in nonsingers. Likewise, its functional connectivity with inferior parietal, frontal, and voice-relevant sensorimotor areas was increased in singers yet decreased in nonsingers. These results indicate that singers relied more on somatosensory feedback, whereas nonsingers depended more critically on auditory feedback. When comparing auditory vs somatosensory feedback involvement, the right anterior insula emerged as the only region for correcting intended vocal output by modulating what is heard or felt as a function of singing experience. We propose the right anterior insula as a key node in the brain's singing network for the integration of signals of salience across multiple sensory and cognitive domains to guide vocal behavior.

  10. Subjective soundscapes qualitative research in the experience and evaluation of environmental noise

    NASA Astrophysics Data System (ADS)

    Flick, Uwe

    2004-05-01

    If the subjective experience and evaluation of environmental noise shall be considered and integrated into the current soundscape research, the use of qualitative research methods used in sociology and psychology will become necessary. A triangulation of research methods for measuring objective noise and for the subjective evaluation of noises and sounds on the background of subjective meanings of health and healthy living will be a fruitful way to a more comprehensive understanding of the phenomenon of soundscapes in the context of health and quality of life. In this contribution, a selection of qualitative research methods will be presented that allows for analyzing subjective experiences with environmental noise. Interviews focusing on narratives of episodes and situations (e.g., the episodic interview, Flick, 2002) will be outlined. Issues of how to assess the quality of qualitative research and its results will be addressed and finally the benefits and limits of the triangulation of different methods (e.g., interviews and focus groups or interviews and physical measures) will be discussed. Research experiences from the author's recent studies on health concepts of health professionals will be used for illustration.

  11. Assessment of an action against environmental noise: Acoustic durability of a pavement surface with crumb rubber.

    PubMed

    Vázquez, V F; Luong, J; Bueno, M; Terán, F; Paje, S E

    2016-01-15

    Environmental noise is a worldwide problem that has an adverse effect in the quality of life of urban population. Some work has shown that there is a correlation between environmental noise and health issues as sleep disturbance or annoyance. This study presents the time evolution of a test track fabricated with an asphalt mixture with 20% of crumb rubber by weight of bitumen, added by the wet process. A complete surface characterization has been performed by determining tire/pavement sound levels, road texture profiles, in-situ dynamic stiffness and sound absorption of compacted and extracted sample cores. Two measurement campaigns were performed: just after mixture laying and after 3 years in service. This study confirms that the use of crumb rubber as a modifier of bituminous binders (CRMB) can improve the pavement characteristics: gap-graded mixtures with crumb rubber can be used in the action plans as urban rehabilitation measure to fight noise pollution. However, this noise reduction seems to decrease with age at a rate of approximately 0.15 dB(A) per year.

  12. On the ability of consumer electronics microphones for environmental noise monitoring.

    PubMed

    Van Renterghem, Timothy; Thomas, Pieter; Dominguez, Frederico; Dauwe, Samuel; Touhafi, Abdellah; Dhoedt, Bart; Botteldooren, Dick

    2011-03-01

    The massive production of microphones for consumer electronics, and the shift from dedicated processing hardware to PC-based systems, opens the way to build affordable, extensive noise measurement networks. Applications include e.g. noise limit and urban soundscape monitoring, and validation of calculated noise maps. Microphones are the critical components of such a network. Therefore, in a first step, some basic characteristics of 8 microphones, distributed over a wide range of price classes, were measured in a standardized way in an anechoic chamber. In a next step, a thorough evaluation was made of the ability of these microphones to be used for environmental noise monitoring. This was done during a continuous, half-year lasting outdoor experiment, characterized by a wide variety of meteorological conditions. While some microphones failed during the course of this test, it was shown that it is possible to identify cheap microphones that highly correlate to the reference microphone during the full test period. When the deviations are expressed in total A-weighted (road traffic) noise levels, values of less than 1 dBA are obtained, in excess to the deviation amongst reference microphones themselves.

  13. Potential problems with environmental sound barriers when used in mitigating surface transportation noise.

    PubMed

    Arenas, Jorge P

    2008-11-01

    The public, increasingly well-informed about the problem of excessive noise, is taking actions for the development of new transport infrastructure projects and improvement of existing infrastructure. In addition, many countries have implemented mandatory Environmental Impact Assessment procedures. As a result, the construction of sound barriers has become a common measure, which can be used by an agency to mitigate potentially significant noise impacts. A sound barrier, eventually, will become part of the surrounding landscape and could be a cause of impact for ecosystems, the road users and those who live alongside the road. Basically, this article discusses these potential effects in the context of environmental assessment procedures. In addition, results of a pilot survey conducted at a residential area affected by the construction of a barrier are presented. Although most residents felt that sleeping conditions improved after the barrier was built, most important negative reactions are the loss of sunlight and visual impact.

  14. The role of large environmental noise in masting: general model and example from pistachio trees.

    PubMed

    Lyles, Danielle; Rosenstock, Todd S; Hastings, Alan; Brown, Patrick H

    2009-08-21

    Masting is synchronous, highly variable reproduction in a plant population, or synchronized boom-bust cycles of reproduction. These pulses of resources have cascading effects through ecosystems, and thus it is important to understand where they come from. How does masting happen and synchronize? In this paper, we suggest a mechanism for this. The mechanism is inspired by data from a pistachio orchard, which suggest that large environmental noise may play a crucial role in inducing masting in plant populations such as pistachio. We test this idea through development and analysis of a mathematical model of plant reproduction. We start with a very simple model, and generalize it based on the current models of plant reproduction and masting. Our results suggest that large environmental noise may indeed be a crucial part of the mechanism of masting in certain types of plant populations, including pistachio. This is a specific example of an important functional consequence of the interactions between stochasticity and nonlinearity.

  15. Neutral dynamics with environmental noise: Age-size statistics and species lifetimes

    NASA Astrophysics Data System (ADS)

    Kessler, David; Suweis, Samir; Formentin, Marco; Shnerb, Nadav M.

    2015-08-01

    Neutral dynamics, where taxa are assumed to be demographically equivalent and their abundance is governed solely by the stochasticity of the underlying birth-death process, has proved itself as an important minimal model that accounts for many empirical datasets in genetics and ecology. However, the restriction of the model to demographic [O (√{N }) ] noise yields relatively slow dynamics that appears to be in conflict with both short-term and long-term characteristics of the observed systems. Here we analyze two of these problems—age-size relationships and species extinction time—in the framework of a neutral theory with both demographic and environmental stochasticity. It turns out that environmentally induced variations of the demographic rates control the long-term dynamics and modify dramatically the predictions of the neutral theory with demographic noise only, yielding much better agreement with empirical data. We consider two prototypes of "zero mean" environmental noise, one which is balanced with regard to the arithmetic abundance, another balanced in the logarithmic (fitness) space, study their species lifetime statistics, and discuss their relevance to realistic models of community dynamics.

  16. EVALUATION OF THE ENVIRONMENTAL NOISE LEVELS IN ABUJA MUNICIPALITY USING MOBILE PHONES

    PubMed Central

    Ibekwe, T.; Folorunso, D.; Ebuta, A.; Amodu, J.; Nwegbu, M.; Mairami, Z.; Liman, I.; Okebaram, C.; Chimdi, C.; Durogbola, B.; Suleiman, H.; Mamven, H.; Baamlong, N.; Dahilo, E.; Gbujie, I.; Ibekwe, P.; Nwaorgu, O.

    2016-01-01

    Background: Noise remains a nuisance which impacts negatively on the physical, social and psychological wellbeing of man. It aggravates chronic illnesses like hypertension and other cardiopulmonary diseases. Unfortunately, increased activities from industrialization and technological transfers/drifts have tumultuously led to increased noise pollution in most of our fast growing cities today and hence the need for concerted efforts in monitoring and regulating our environmental noise. Objective: To assess the equivalent noise level (Leq) in Abuja municipality and promote a simple method for regular assessment of Leq within our environment. Method: This is a cross-sectional community based study of the environmental Leq of Abuja municipality conducted between January 2014 and January 2016. The city was divided into 12 segments including residential, business and market areas via the Abuja Geographic Information System. The major markets were captured separately on a different scale. Measurements were taken with the mobile phone softwares having validated this with Extech 407730 digital sound level meter, serial no Z310135. Leq(A) were measured at different points and hours of the day and night. The average Leq(A) were classified according to localities and compared with WHO standard safety levels. Results: LeqD ranged 71-92dB(A); 42-79dB(A) and 69-90dB(A) in business/ parks, residential and market places respectively. The Night measurements were similar 18dB(A)-56dB(A) and the day-night Leq(A)=77.2dB(A) and 90.4dB(A) for residential and business zones. Conclusion: The night noise levels are satisfactory but the day and day-night levels are above the recommended tolerable values by WHO and therefore urgently call for awareness and legislative regulations. PMID:28337089

  17. Do outdoor environmental noise and atmospheric NO2 levels spatially overlap in urban areas?

    PubMed

    Tenailleau, Quentin M; Bernard, Nadine; Pujol, Sophie; Parmentier, Anne-Laure; Boilleaut, Mathieu; Houot, Hélène; Joly, Daniel; Mauny, Frédéric

    2016-07-01

    The urban environment holds numerous emission sources for air and noise pollution, creating optimum conditions for environmental multi-exposure situations. Evaluation of the joint-exposure levels is the main obstacle for multi-exposure studies and one of the biggest challenges of the next decade. The present study aims to describe the noise/NO2 multi-exposure situations in the urban environment by exploring the possible discordant and concordant situations of both exposures. Fine-scale diffusion models were developed in the European medium-sized city of Besançon (France), and a classification method was used to evaluate the multi-exposure situations in the façade perimeter of 10,825 buildings. Although correlated (Pearson's r = 0.64, p < 0.01), urban spatial distributions of the noise and NO2 around buildings do not overlap, and 30% of the buildings were considered to be discordant in terms of the noise and NO2 exposure levels. This discrepancy is spatially structured and associated with variables describing the building's environment. Our results support the presence of several co-existing, multi-exposure situations across the city impacted by both the urban morphology and the emission and diffusion/propagation phases of each pollutant. Identifying the mechanisms of discrepancy and convergence of multi-exposure situations could help improve the health risk assessment and public health.

  18. Improving environmental noise suppression for micronewton force sensing based on electrostatic by injecting air damping.

    PubMed

    Zheng, Yelong; Song, Le; Hu, Gang; Zhao, Meirong; Tian, Yanling; Zhang, Zihui; Fang, Fengzhou

    2014-05-01

    A micro/nano force can be traced to the International System of Units by means of an electrostatic force balance weight system. However, the micro/nano force measurement system is susceptible to environmental disturbances. Various methods have been proposed to reduce the effect of environmental disturbances and obtain high resolution and fast response. In this paper, we introduce a combination of air damping and inherent damping from the internal molecular friction of spring suspension. This will optimize system stability and improve environmental noise suppression. Results from the air damping model show that the damping ratio increases from 0.0005 to 0.1, which improves the vibration resistance. We found that the system with air damping has the advantages of fast response and low scatter.

  19. Unconventional Impacts from Unconventional Hydropower Devices: The Environmental Effects of Noise, Electromagnetic Fields, and other Stressors

    NASA Astrophysics Data System (ADS)

    Bevelhimer, M.; Cada, G. F.

    2011-12-01

    Conventional dam-based hydropower production produces a variety of environmental stressors that have been debated and confronted for decades. In-current hydrokinetic devices present some of the same or analogous stressors (e.g., changes in sediment transport and deposition, interference with animal movements and migrations, and strike by rotor blades) and some potentially new stressors (e.g., noise during operation, emission of electromagnetic fields [EMF], and toxicity of paints, lubricants, and antifouling coatings). The types of hydrokinetic devices being proposed and tested are varied, as are the locations where they could be deployed, i.e., coastal, estuarine, and big rivers. Differences in hydrology, device type, and the affected aquatic community (marine, estuarine, and riverine) will likely result in a different suite of environmental concerns for each project. Studies are underway at the U.S. Department of Energy's national laboratories to characterize the level of exposure to these stressors and to measure environmental response where possible. In this presentation we present results of studies on EMF, noise, and benthic habitat alteration relevant to hydrokinetic device operation in large rivers. In laboratory studies we tested the behavioral response of a variety of fish and invertebrate organisms to exposure to DC and AC EMF. Our findings suggest that lake sturgeon may be susceptible to EMF like that emitted from underwater cables, but most other species tested are not. Based on recordings of various underwater noise sources, we will show how the spectral density of noises created by hydrokinetic devices compares to that from other anthropogenic sources and natural sources. We will also report the results of hydroacoustic surveys that show how sediments are redistributed behind pilings like those that could be used for mounting hydrokinetic devices. The potential effects of these stressors will be discussed in the context of possible fish population

  20. Masks: Interpretations and Variations.

    ERIC Educational Resources Information Center

    Basso, Robert

    1990-01-01

    Presents a high school art teacher's views of and experiences with masks. Outlines a maskmaking activity in which students were required to create variations on existing masks. Emphasizes use of experimental materials. Displays examples of student-created masks. (DB)

  1. Psychometric functions for informational masking

    NASA Astrophysics Data System (ADS)

    Lutfi, Robert A.; Kistler, Doris J.; Callahan, Michael R.; Wightman, Frederic L.

    2003-12-01

    The term informational masking has traditionally been used to refer to elevations in signal threshold resulting from masker uncertainty. In the present study, the method of constant stimuli was used to obtain complete psychometric functions (PFs) from 44 normal-hearing listeners in conditions known to produce varying amounts of informational masking. The listener's task was to detect a pure-tone signal in the presence of a broadband noise masker (low masker uncertainty) and in the presence of multitone maskers with frequencies and amplitudes that varied at random from one presentation to the next (high masker uncertainty). Relative to the broadband noise condition, significant reductions were observed in both the slope and the upper asymptote of the PF for multitone maskers producing large amounts of informational masking. Slope was affected more for some listeners and conditions while asymptote was affected more for others; consequently, neither parameter alone was highly predictive of individual thresholds or the amount of informational masking. Mean slopes and asymptotes varied nonmonotonically with the number of masker components in a manner similar to mean thresholds, particularly when the estimated effect of energetic masking on thresholds was subtracted out. As in past studies, the threshold data were well described by a model in which trial-by-trial judgments are based on a weighted sum of levels in dB at the output of independent auditory filters. The psychometric data, however, complicated the model's interpretation in two ways: First, they suggested that, depending on the listener and condition, the weights can either reflect a fixed influence of masker components on each trial or the effect of occasionally mistaking a masker component for the signal from trial to trial. Second, they indicated that in either case the variance of the underlying decision variable as estimated from PF slope is not by itself great enough to account for the observed changes

  2. Psychometric functions for informational masking

    PubMed Central

    Lutfi, Robert A.; Kistler, Doris J.; Callahan, Michael R.; Wightman, Frederic L.

    2010-01-01

    The term informational masking has traditionally been used to refer to elevations in signal threshold resulting from masker uncertainty. In the present study, the method of constant stimuli was used to obtain complete psychometric functions (PFs) from 44 normal-hearing listeners in conditions known to produce varying amounts of informational masking. The listener’s task was to detect a pure-tone signal in the presence of a broadband noise masker (low masker uncertainty) and in the presence of multitone maskers with frequencies and amplitudes that varied at random from one presentation to the next (high masker uncertainty). Relative to the broadband noise condition, significant reductions were observed in both the slope and the upper asymptote of the PF for multitone maskers producing large amounts of informational masking. Slope was affected more for some listeners and conditions while asymptote was affected more for others; consequently, neither parameter alone was highly predictive of individual thresholds or the amount of informational masking. Mean slopes and asymptotes varied nonmonotonically with the number of masker components in a manner similar to mean thresholds, particularly when the estimated effect of energetic masking on thresholds was subtracted out. As in past studies, the threshold data were well described by a model in which trial-by-trial judgments are based on a weighted sum of levels in dB at the output of independent auditory filters. The psychometric data, however, complicated the model’s interpretation in two ways: First, they suggested that, depending on the listener and condition, the weights can either reflect a fixed influence of masker components on each trial or the effect of occasionally mistaking a masker component for the signal from trial to trial. Second, they indicated that in either case the variance of the underlying decision variable as estimated from PF slope is not by itself great enough to account for the observed

  3. Sub-Surface Radar for the EJSM mission: discussion on environmental noise limiting performance

    NASA Astrophysics Data System (ADS)

    Alberti, G.; Berquin, Y.; Cecconi, B.; Bruzzone, L.; Kofman, W.; Herique, A.; Schenk, P.; Mattei, S.

    2011-10-01

    The Europa Jupiter System Mission (EJSM) is one of the major European Space Agency (ESA) missions in the Solar System currently under study. It is aimed at exploring Jupiter and its icy moon Ganymede. The Sub-Surface Radar (SSR) instrument is a radar sounder system at low frequency (HF/VHF band) designed to penetrate the surface of Ganymede icy moon of Jupiter for performing a subsurface analysis with a relatively high range resolution. The paper addresses the main sources of environmental noises that can limit the overall performance of the radar: the presence of a relevant Jupiter radio emission and the clutter caused by characteristics of planet's surface.

  4. Environmental Noise Annoyance and Mental Health in Adults: Findings from the Cross-Sectional German Health Update (GEDA) Study 2012

    PubMed Central

    Hammersen, Friederike; Niemann, Hildegard; Hoebel, Jens

    2016-01-01

    The health implications of environmental noise, especially cardiovascular effects, have been studied intensively. Research on associations between noise and mental health, however, has shown contradictory results. The present study examined associations between individual levels of noise annoyance due to noise from various sources in the living environment and mental health of adults in Germany. It evaluated whether these associations persisted after adjusting for potential covariates. Data were obtained from the cross-sectional “German Health Update” study 2012 (GEDA 2012), a national health interview survey among adults in Germany conducted by the Robert Koch Institute (n = 19,294). Noise annoyance questions referred to overall noise and that from road traffic, neighbours, and air traffic. Mental health was measured with the five-item Mental Health Inventory. Bivariate analysis showed associations between high levels of noise annoyance and impaired mental health for all noise sources except air traffic. After adjusting for covariates (sociodemographic factors, chronic disease, and social support), both men and women who reported high overall noise annoyance showed more than doubled odds of impaired mental health compared to those who were not annoyed. The odds of impaired mental health in the highest noise annoyance category from road traffic and neighbours were also significantly increased. These findings indicate that high noise annoyance is associated with impaired mental health and that this association can vary with the source of environmental noise. Further research on covariates of this association is necessary. Particularly, longitudinal data are required to establish the direction of associations and to address questions of causality. PMID:27681736

  5. Effects of environmental noise on cognitive (dys)functions in schizophrenia: A pilot within-subjects experimental study.

    PubMed

    Wright, Bernice; Peters, Emmanuelle; Ettinger, Ulrich; Kuipers, Elizabeth; Kumari, Veena

    2016-05-01

    Cognitive impairment, particularly in attention, memory and executive function domains, is commonly present and associated with poor functional outcomes in schizophrenia. In healthy adults, environmental noise adversely affects many cognitive domains, including those known to be compromised in schizophrenia. This pilot study examined whether environmental noise causes further cognitive deterioration in a small sample of people with schizophrenia. Eighteen outpatients with schizophrenia on stable doses of antipsychotics and 18 age and sex-matched healthy participants were assessed on a comprehensive cognitive battery including measures of psychomotor speed, attention, executive functioning, working memory, and verbal learning and memory under three different conditions [quiet: ~30dB(A); urban noise: building site noise, 68-78dB(A); and social noise: background babble and footsteps from a crowded hall without any discernible words, 68-78dB(A)], 7-14days apart, with counter-balanced presentation of noise conditions across participants of both groups. The results showed widespread cognitive impairment in patients under all conditions, and noise-induced impairments of equal magnitude on specific cognitive functions in both groups. Both patient and healthy participant groups showed significant disruption of delayed verbal recall and recognition by urban and social noise, and of working memory by social noise, relative to the quiet condition. Performance under urban and social noise did not differ significantly from each other for any cognitive measure in either group. We conclude that noise has adverse effects on the verbal and working memory domains in schizophrenia patients and healthy participants. This may be particularly problematic for patients as it worsens their pre-existing cognitive deficits.

  6. Effects of environmental noise on cognitive (dys)functions in schizophrenia: A pilot within-subjects experimental study

    PubMed Central

    Wright, Bernice; Peters, Emmanuelle; Ettinger, Ulrich; Kuipers, Elizabeth; Kumari, Veena

    2016-01-01

    Cognitive impairment, particularly in attention, memory and executive function domains, is commonly present and associated with poor functional outcomes in schizophrenia. In healthy adults, environmental noise adversely affects many cognitive domains, including those known to be compromised in schizophrenia. This pilot study examined whether environmental noise causes further cognitive deterioration in a small sample of people with schizophrenia. Eighteen outpatients with schizophrenia on stable doses of antipsychotics and 18 age and sex-matched healthy participants were assessed on a comprehensive cognitive battery including measures of psychomotor speed, attention, executive functioning, working memory, and verbal learning and memory under three different conditions [quiet: ~ 30 dB(A); urban noise: building site noise, 68–78 dB(A); and social noise: background babble and footsteps from a crowded hall without any discernible words, 68–78 dB(A)], 7–14 days apart, with counter-balanced presentation of noise conditions across participants of both groups. The results showed widespread cognitive impairment in patients under all conditions, and noise-induced impairments of equal magnitude on specific cognitive functions in both groups. Both patient and healthy participant groups showed significant disruption of delayed verbal recall and recognition by urban and social noise, and of working memory by social noise, relative to the quiet condition. Performance under urban and social noise did not differ significantly from each other for any cognitive measure in either group. We conclude that noise has adverse effects on the verbal and working memory domains in schizophrenia patients and healthy participants. This may be particularly problematic for patients as it worsens their pre-existing cognitive deficits. PMID:27017491

  7. Masks and Other Disguises.

    ERIC Educational Resources Information Center

    Ploghoft, Debra

    Instructions for making simple masks are provided in this guide for teachers of elementary children. Directions with illustrations are given for constructing masks from paper plates, construction paper, plastic milk jugs, and papier-mache. Ideas include a clown mask, a flower mask, a top hat, a paper crown, and "Groucho" glasses. Types…

  8. Measuring combined exposure to environmental pressures in urban areas: an air quality and noise pollution assessment approach.

    PubMed

    Vlachokostas, Ch; Achillas, Ch; Michailidou, A V; Moussiopoulos, Nu

    2012-02-01

    This study presents a methodological scheme developed to provide a combined air and noise pollution exposure assessment based on measurements from personal portable monitors. Provided that air and noise pollution are considered in a co-exposure approach, they represent a significant environmental hazard to public health. The methodology is demonstrated for the city of Thessaloniki, Greece. The results of an extensive field campaign are presented and the variations in personal exposure between modes of transport, routes, streets and transport microenvironments are evaluated. Air pollution and noise measurements were performed simultaneously along several commuting routes, during the morning and evening rush hours. Combined exposure to environmental pollutants is highlighted based on the Combined Exposure Factor (CEF) and Combined Dose and Exposure Factor (CDEF). The CDEF takes into account the potential relative uptake of each pollutant by considering the physical activities of each citizen. Rather than viewing environmental pollutants separately for planning and environmental sustainability considerations, the possibility of an easy-to-comprehend co-exposure approach based on these two indices is demonstrated. Furthermore, they provide for the first time a combined exposure assessment to these environmental pollutants for Thessaloniki and in this sense they could be of importance for local public authorities and decision makers. A considerable environmental burden for the citizens of Thessaloniki, especially for VOCs and noise pollution levels is observed. The material herein points out the importance of measuring public health stressors and the necessity of considering urban environmental pollution in a holistic way.

  9. Speech recognition index of workers with tinnitus exposed to environmental or occupational noise: a comparative study

    PubMed Central

    2012-01-01

    Introduction Tinnitus is considered the third worst symptom affecting humans. The aim of this article is to assess complaints by workers with tinnitus exposed to environmental and occupational noise. Methodology 495 workers went through an epidemiological survey at the Audiology Department of the Center for Studies on Workers’ Health and Human Ecology, from 2003 to 2007. The workers underwent tonal and vocal audiometry, preceded by a clinical and occupational history questionnaire. Two-factor ANOVA and Tukey were the statistical tests used. All the analysis set statistical significance at α=5%. Findings There was a higher prevalence of occupational tinnitus (73.7%), a predominance of female domestic workers (65.4%) in cases of environmental exposure, and predominance of male construction workers (71.5%) for occupational exposure. There was a significant difference in workers with hearing loss, who showed a mean speech recognition index (SRI) of 85%, as compared to healthy workers with a mean SRI greater than 93.5%. Signs and symptoms, speech perception, and interference in sound localization with the type of noise exposure (environmental versus occupational) comparisons found no significant differences. Conclusion Studied group’s high prevalence of tinnitus, major difficulties in speech recognition with hearing loss and the presence of individuals with normal hearing with both types of exposure justify the importance of measures in health promotion, prevention, and hearing surveillance. The findings highlight the importance of valuing the patients’ own perception as the first indication of tinnitus and hearing loss in order to help develop appropriate public policies within the Unified National Health System (SUS). PMID:23259813

  10. How Might People Near National Roads Be Affected by Traffic Noise as Electric Vehicles Increase in Number? A Laboratory Study of Subjective Evaluations of Environmental Noise.

    PubMed

    Walker, Ian; Kennedy, John; Martin, Susanna; Rice, Henry

    2016-01-01

    We face a likely shift to electric vehicles (EVs) but the environmental and human consequences of this are not yet well understood. Simulated auditory traffic scenes were synthesized from recordings of real conventional and EVs. These sounded similar to what might be heard by a person near a major national road. Versions of the simulation had 0%, 20%, 40%, 60%, 80% and 100% EVs. Participants heard the auditory scenes in random order, rating each on five perceptual dimensions such as pleasant-unpleasant and relaxing-stressful. Ratings of traffic noise were, overall, towards the negative end of these scales, but improved significantly when there were high proportions of EVs in the traffic mix, particularly when there were 80% or 100% EVs. This suggests a shift towards a high proportion of EVs is likely to improve the subjective experiences of people exposed to traffic noise from major roads. The effects were not a simple result of EVs being quieter: ratings of bandpass-filtered versions of the recordings suggested that people's perceptions of traffic noise were specifically influenced by energy in the 500-2000 Hz band. Engineering countermeasures to reduce noise in this band might be effective for improving the subjective experience of people living or working near major roads, even for conventional vehicles; energy in the 0-100 Hz band was particularly associated with people identifying sound as 'quiet' and, again, this might feed into engineering to reduce the impact of traffic noise on people.

  11. How Might People Near National Roads Be Affected by Traffic Noise as Electric Vehicles Increase in Number? A Laboratory Study of Subjective Evaluations of Environmental Noise

    PubMed Central

    Walker, Ian; Kennedy, John; Martin, Susanna; Rice, Henry

    2016-01-01

    We face a likely shift to electric vehicles (EVs) but the environmental and human consequences of this are not yet well understood. Simulated auditory traffic scenes were synthesized from recordings of real conventional and EVs. These sounded similar to what might be heard by a person near a major national road. Versions of the simulation had 0%, 20%, 40%, 60%, 80% and 100% EVs. Participants heard the auditory scenes in random order, rating each on five perceptual dimensions such as pleasant–unpleasant and relaxing–stressful. Ratings of traffic noise were, overall, towards the negative end of these scales, but improved significantly when there were high proportions of EVs in the traffic mix, particularly when there were 80% or 100% EVs. This suggests a shift towards a high proportion of EVs is likely to improve the subjective experiences of people exposed to traffic noise from major roads. The effects were not a simple result of EVs being quieter: ratings of bandpass-filtered versions of the recordings suggested that people’s perceptions of traffic noise were specifically influenced by energy in the 500–2000 Hz band. Engineering countermeasures to reduce noise in this band might be effective for improving the subjective experience of people living or working near major roads, even for conventional vehicles; energy in the 0–100 Hz band was particularly associated with people identifying sound as ‘quiet’ and, again, this might feed into engineering to reduce the impact of traffic noise on people. PMID:26938865

  12. Airport environmental noise mapping and land use management as an environmental protection action policy tool. The case of the Larnaka International Airport (Cyprus).

    PubMed

    Vogiatzis, Konstantinos

    2012-05-01

    The evidence from epidemiological studies on the association between exposure to traffic and aircraft noise and hypertension and ischemic heart disease has increased during the recent years. Both road traffic and aircraft noise increase the risk of high blood pressure. Environmental noise mapping, as per the 2002/49/EC Directive, is an obligation of all European Union (EU) member states. In the framework of the present article a complete Strategic Noise Mapping research and Action Noise Plans assessment and evaluation are presented and aim to access land use management as an effective tool for protection from aircraft noise. The case of the Larnaka International Airport in Cyprus, a typical Mediterranean airport, (considered as a "large airport" according to the above EU Directive and the recent Cyprus Legislation Law No. 224(Ι)/2004), is presented. In this paper a review of both assessment and action implementation procedures focusing on the dominant--in the area--aircraft traffic noise is presented, with emphasis to (a) a full calculation of Strategic Noise Map (SNM) scenarios of actual and future airport operation using the ECAC.CEAC Doc 29 methodology for both EU common indicators L(den) and L(night) in scales of 5 dB, (b) a full evaluation of results with emphasis to the Larnaka greater area land uses and the exposure of inhabitants in residences in various levels of environmental noise, and (c) a full evaluation of Noise Action Plans (NAP) introducing especially a new land use management scheme for the future Larnaka Town Land Use Plan.

  13. Does environmental confounding mask pleiotropic effects of a multiple sclerosis susceptibility variant on vitamin D in psychosis?

    PubMed Central

    Iyegbe, Conrad O; Acharya, Anita; Lally, John; Gardner-Sood, Poonam; Smith, Louise S; Smith, Shubulade; Murray, Robin; Howes, Oliver; Gaughran, Fiona

    2015-01-01

    Background: This work addresses the existing and emerging evidence of overlap within the environmental and genetic profiles of multiple sclerosis (MS) and schizophrenia. Aims: To investigate whether a genetic risk factor for MS (rs703842), whose variation is indicative of vitamin D status in the disorder, could also be a determinant of vitamin D status in chronic psychosis patients. Methods: A cohort of 224 chronic psychosis cases was phenotyped and biologically profiled. The relationship between rs703842 and physiological vitamin D status in the blood plasma was assessed by logistic regression. Deficiency was defined as a blood plasma concentration below 10 ng/µl. Potential environmental confounders of the vitamin D status were considered as part of the analysis. Results: We report suggestive evidence of an association with vitamin D status in established psychosis (ßstandardized=0.51, P=0.04). The logistic model fit significantly benefited from controlling for body mass index, depression and ethnicity (χ2=91.7; 2 degrees of freedom (df); P=1.2×1020). Conclusions: The results suggest that, in addition to lifestyle changes that accompany the onset of illness, vitamin D dysregulation in psychosis has a genetic component that links into MS. Further, comprehensive studies are needed to evaluate this prospect. PMID:27336042

  14. Informational masking and musical training

    NASA Astrophysics Data System (ADS)

    Oxenham, Andrew J.; Fligor, Brian J.; Mason, Christine R.; Kidd, Gerald

    2003-09-01

    The relationship between musical training and informational masking was studied for 24 young adult listeners with normal hearing. The listeners were divided into two groups based on musical training. In one group, the listeners had little or no musical training; the other group was comprised of highly trained, currently active musicians. The hypothesis was that musicians may be less susceptible to informational masking, which is thought to reflect central, rather than peripheral, limitations on the processing of sound. Masked thresholds were measured in two conditions, similar to those used by Kidd et al. [J. Acoust. Soc. Am. 95, 3475-3480 (1994)]. In both conditions the signal was comprised of a series of repeated tone bursts at 1 kHz. The masker was comprised of a series of multitone bursts, gated with the signal. In one condition the frequencies of the masker were selected randomly for each burst; in the other condition the masker frequencies were selected randomly for the first burst of each interval and then remained constant throughout the interval. The difference in thresholds between the two conditions was taken as a measure of informational masking. Frequency selectivity, using the notched-noise method, was also estimated in the two groups. The results showed no difference in frequency selectivity between the two groups, but showed a large and significant difference in the amount of informational masking between musically trained and untrained listeners. This informational masking task, which requires no knowledge specific to musical training (such as note or interval names) and is generally not susceptible to systematic short- or medium-term training effects, may provide a basis for further studies of analytic listening abilities in different populations.

  15. Environmental Resources of Selected Areas of Hawaii: Climate, Ambient Air Quality, and Noise (DRAFT)

    SciTech Connect

    Lombardi, D.A.; Blasing, T.J.; Easterly, C.E.; Hamilton, C.B.

    1994-06-01

    This report has been prepared to make available and archive background scientific data and related information on climate, ambient air quality, and ambient noise levels collected during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice in the Federal Register on May 17, 1994 withdrawing its Notice of Intent of February 14, 1992, to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The report presents a general description of the climate and air quality for the islands of Hawaii (henceforth referred to as Hawaii), Maui, and Oahu. It also presents a literature review as baseline information on the health effects of hydrogen sulfide. the scientific background data and related information is being made available for use by others in conducting future scientific research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  16. Environmental resources of selected areas of Hawaii: Climate, ambient air quality, and noise

    SciTech Connect

    Lombardi, D.A.; Blasing, T.J.; Easterly, C.E.; Reed, R.M.; Hamilton, C.B.

    1995-03-01

    This report has been prepared to make available and archive background scientific data and related information on climate, ambient air quality, and ambient noise levels collected during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice withdrawing its Notice of Intent to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The report presents a general description of the climate add air quality for the islands of Hawaii (henceforth referred to as Hawaii), Maui and Oahu. It also presents a literature review as baseline information on the health effects of sulfide. The scientific background data and related information is being made available for use by others in conducting future scientific research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  17. An environmental index of noise and light pollution at EU by spatial correlation of quiet and unlit areas.

    PubMed

    Votsi, Nefta-Eleftheria P; Kallimanis, Athanasios S; Pantis, Ioannis D

    2017-02-01

    Quietness exists in places without human induced noise sources and could offer multiple benefits to citizens. Unlit areas are sites free of human intense interference at night time. The aim of this research is to develop an integrated environmental index of noise and light pollution. In order to achieve this goal the spatial pattern of quietness and darkness of Europe was identified, as well as their overlap. The environmental index revealed that the spatial patterns of Quiet and Unlit Areas differ to a great extent highlighting the importance of preserving quietness as well as darkness in EU. The spatial overlap of these two environmental characteristics covers 32.06% of EU surface area, which could be considered a feasible threshold for protection. This diurnal and nocturnal metric of environmental quality accompanied with all direct and indirect benefits to human well-being could indicate a target for environmental protection in the EU policy and practices.

  18. Environmentally Responsible Aviation: Propulsion Research to Enable Fuel Burn, Noise and Emissions Reduction

    NASA Technical Reports Server (NTRS)

    Van Zante, Dale E.; Suder, Kenneth L.

    2015-01-01

    The NASA Environmentally Responsible Aviation (ERA) program is maturing technologies to enable simultaneous reduction of fuel burn, noise and emissions from an aircraft engine system. Three engine related Integrated Technology Demonstrations (ITDs) have been completed at Glenn Research Center in collaboration with Pratt Whitney, General Electric and the Federal Aviation Administration. The engine technologies being matured are a low NOx, fuel flexible combustor in partnership with Pratt Whitney, an ultra-high bypass, ducted propulsor system in partnership with Pratt Whitney FAA and high pressure ratio, front-stage core compressor technology in partnership with General Electric. The technical rationale, test configurations and overall results from the test series in each ITD are described. ERA is using system analysis to project the benefits of the ITD technologies on potential aircraft systems in the 2025 timeframe. Data from the ITD experiments were used to guide the system analysis assumptions. Results from the current assessments for fuel burn, noise and oxides of nitrogen emissions are presented.

  19. Environmentally Responsible Aviation: Propulsion Research to Enable Fuel Burn, Noise and Emissions Reduction

    NASA Technical Reports Server (NTRS)

    Van Zante, Dale; Suder, Kenneth

    2015-01-01

    The NASA Environmentally Responsible Aviation (ERA) program is maturing technologies to enable simultaneous reduction of fuel burn, noise and emissions from an aircraft engine system. Three engine related Integrated Technology Demonstrations (ITDs) have been completed at Glenn Research Center in collaboration with Pratt Whitney, General Electric and the Federal Aviation Administration. The engine technologies being matured are: a low NOx, fuel flexible combustor in partnership with Pratt Whitney; an ultra-high bypass, ducted propulsor system in partnership with Pratt Whitney and FAA; and high pressure ratio, front-stage core compressor technology in partnership with General Electric. The technical rationale, test configurations and overall results from the test series in each ITD are described. ERA is using system analysis to project the benefits of the ITD technologies on potential aircraft systems in the 2025 timeframe. Data from the ITD experiments were used to guide the system analysis assumptions. Results from the current assessments for fuel burn, noise and oxides of nitrogen emissions are presented.

  20. Selective attention and the auditory vertex potential. I - Effects of stimulus delivery rate. II - Effects of signal intensity and masking noise

    NASA Technical Reports Server (NTRS)

    Schwent, V. L.; Hillyard, S. A.; Galambos, R.

    1976-01-01

    The effects of varying the rate of delivery of dichotic tone pip stimuli on selective attention measured by evoked-potential amplitudes and signal detectability scores were studied. The subjects attended to one channel (ear) of tones, ignored the other, and pressed a button whenever occasional targets - tones of a slightly higher pitch were detected in the attended ear. Under separate conditions, randomized interstimulus intervals were short, medium, and long. Another study compared the effects of attention on the N1 component of the auditory evoked potential for tone pips presented alone and when white noise was added to make the tones barely above detectability threshold in a three-channel listening task. Major conclusions are that (1) N1 is enlarged to stimuli in an attended channel only in the short interstimulus interval condition (averaging 350 msec), (2) N1 and P3 are related to different modes of selective attention, and (3) attention selectivity in multichannel listening task is greater when tones are faint and/or difficult to detect.

  1. Incomplete figure perception and invisible masking.

    PubMed

    Chikhman, Valery; Shelepin, Yuri; Foreman, Nigel; Merkuljev, Aleksey; Pronin, Sergey

    2006-01-01

    The Gollin test (measuring recognition thresholds for fragmented line drawings of everyday objects and animals) has traditionally been regarded as a test of incomplete figure perception or 'closure', though there is a debate about how such closure is achieved. Here, figural incompleteness is considered to be the result of masking, such that absence of contour elements of a fragmented figure is the result of the influence of an 'invisible' mask. It is as though the figure is partly obscured by a mask having parameters identical to those of the background. This mask is 'invisible' only consciously, but for the early stages of visual processing it is real and has properties of multiplicative noise. Incomplete Gollin figures were modeled as the figure covered by the mask with randomly distributed transparent and opaque patches. We adjusted the statistical characteristics of the contour image and empty noise patches and processed those using spatial and spatial-frequency measures. Across 73 figures, despite inter-subject variability, mean recognition threshold was always approximately 15% of total contour in naive observers. Recognition worsened with increasing spectral similarity between the figure and the 'invisible' mask. Near threshold, the spectrum of the fragmented image was equally similar to that of the 'invisible' mask and complete image. The correlation between spectral parameters of figures at threshold and complete figures was greatest for figures that were most easily recognised. Across test sessions, thresholds reduced when either figure or mask parameters were familiar. We argue that recognition thresholds for Gollin stimuli in part reflect the extraction of signal from noise.

  2. Measurement of Regional Environmental Noise by Use of a Pc-Based System. A Application to the Noise Near Airport ``G. Marconi'' in Bologna

    NASA Astrophysics Data System (ADS)

    Sakai, H.; Sato, S.; Prodi, N.; Pompoli, R.

    2001-03-01

    Measurements of aircraft noise were made at the airport "G. Marconi" in Bologna by using a measurement system for regional environmental noise. The system is based on the model of the human auditory-brain system, which is based on the interplay of autocorrelators and an interaural cross-correlator acting on the pressure signals arriving at the ear entrances, and takes into account the specialization of left and right human cerebral hemispheres (see reference [8]). Measurements were taken through dual microphones at ear entrances of a dummy head. The aircraft noise was characterized with the following physical factors calculated from the autocorrelation function (ACF) and interaural cross-correlation function (IACF) for binaural signals. From the ACF analysis, (1) energy represented at the origin of delay,Φ (0), (2) effective duration of the envelope of the normalized ACF, τe, (3) the delay time of the first peak, τ1, and (4) its amplitude, φ1were extracted. From the IACF analysis, (5) IACC, (6) interaural delay time at which the IACC is defined, τIACC, and (7) width of the IACF at the τIACC, WIACCwere extracted. The factorΦ (0) can be represented as the geometrical mean of the energies at both ears. A noise source may be identified by these factors as timbre.

  3. The binaural masking-level difference of mandarin tone detection and the binaural intelligibility-level difference of mandarin tone recognition in the presence of speech-spectrum noise.

    PubMed

    Ho, Cheng-Yu; Li, Pei-Chun; Chiang, Yuan-Chuan; Young, Shuenn-Tsong; Chu, Woei-Chyn

    2015-01-01

    Binaural hearing involves using information relating to the differences between the signals that arrive at the two ears, and it can make it easier to detect and recognize signals in a noisy environment. This phenomenon of binaural hearing is quantified in laboratory studies as the binaural masking-level difference (BMLD). Mandarin is one of the most commonly used languages, but there are no publication values of BMLD or BILD based on Mandarin tones. Therefore, this study investigated the BMLD and BILD of Mandarin tones. The BMLDs of Mandarin tone detection were measured based on the detection threshold differences for the four tones of the voiced vowels /i/ (i.e., /i1/, /i2/, /i3/, and /i4/) and /u/ (i.e., /u1/, /u2/, /u3/, and /u4/) in the presence of speech-spectrum noise when presented interaurally in phase (S0N0) and interaurally in antiphase (SπN0). The BILDs of Mandarin tone recognition in speech-spectrum noise were determined as the differences in the target-to-masker ratio (TMR) required for 50% correct tone recognitions between the S0N0 and SπN0 conditions. The detection thresholds for the four tones of /i/ and /u/ differed significantly (p<0.001) between the S0N0 and SπN0 conditions. The average detection thresholds of Mandarin tones were all lower in the SπN0 condition than in the S0N0 condition, and the BMLDs ranged from 7.3 to 11.5 dB. The TMR for 50% correct Mandarin tone recognitions differed significantly (p<0.001) between the S0N0 and SπN0 conditions, at -13.4 and -18.0 dB, respectively, with a mean BILD of 4.6 dB. The study showed that the thresholds of Mandarin tone detection and recognition in the presence of speech-spectrum noise are improved when phase inversion is applied to the target speech. The average BILDs of Mandarin tones are smaller than the average BMLDs of Mandarin tones.

  4. A general procedure to generate models for urban environmental-noise pollution using feature selection and machine learning methods.

    PubMed

    Torija, Antonio J; Ruiz, Diego P

    2015-02-01

    The prediction of environmental noise in urban environments requires the solution of a complex and non-linear problem, since there are complex relationships among the multitude of variables involved in the characterization and modelling of environmental noise and environmental-noise magnitudes. Moreover, the inclusion of the great spatial heterogeneity characteristic of urban environments seems to be essential in order to achieve an accurate environmental-noise prediction in cities. This problem is addressed in this paper, where a procedure based on feature-selection techniques and machine-learning regression methods is proposed and applied to this environmental problem. Three machine-learning regression methods, which are considered very robust in solving non-linear problems, are used to estimate the energy-equivalent sound-pressure level descriptor (LAeq). These three methods are: (i) multilayer perceptron (MLP), (ii) sequential minimal optimisation (SMO), and (iii) Gaussian processes for regression (GPR). In addition, because of the high number of input variables involved in environmental-noise modelling and estimation in urban environments, which make LAeq prediction models quite complex and costly in terms of time and resources for application to real situations, three different techniques are used to approach feature selection or data reduction. The feature-selection techniques used are: (i) correlation-based feature-subset selection (CFS), (ii) wrapper for feature-subset selection (WFS), and the data reduction technique is principal-component analysis (PCA). The subsequent analysis leads to a proposal of different schemes, depending on the needs regarding data collection and accuracy. The use of WFS as the feature-selection technique with the implementation of SMO or GPR as regression algorithm provides the best LAeq estimation (R(2)=0.94 and mean absolute error (MAE)=1.14-1.16 dB(A)).

  5. Methods and Tools for Monitoring and Prediction of the Large-Scale Environmental Impact of Railway Noise

    NASA Astrophysics Data System (ADS)

    ELBERS, F. B. J.

    2000-03-01

    Due to environmental impact regulations there is a demand for methods and tools to determine noise reception levels near railway lines. Currently, a wide variety of methods and tools is available. Fast computers now enable us to develop powerful tools that combine simplified prediction methods with GIS systems. These new systems allow the study of noise reception levels and environmental impact on a large-scale (complete network, national or international), while more detailed and labour-intensive methods and tools are used when demanded by law. This paper presents a brief overview of the noise prediction methods and tools used in the Netherlands. The focus is on the advantages and restrictions of the different methods. Finally, the paper gives an overview of the actual advantages and restrictions of the recently extended Gerano method Gerano98 (Geographic Railway Noise). Gerano was originally based on the “basic Dutch calculation rules for railway noise”. Gerano98 was extended using simplified prediction schemes for the most relevant parts of the “detailed Dutch calculation rules for railway noise”. This most recent calculation method, combined with geographic input features, provides the possibility of determining noise impact and the noise measures to be taken on both the medium and large scale. Examples of the application of the methods and tools to specific (medium- and large-scale) projects are provided. The medium-scale project presents the results of a selection of the prefered line between Amsterdam and Zwolle. The large-scale project (the complete Dutch railway network) shows the results of the comparison of noise measures at source with noise barriers or housing insulation. For both projects the applicability and the usefulness of the methods in these situations is discussed. In conclusion four developments of the Gerano concept are described which have recently been finished or will be so in the near future.

  6. The effect of complementary music therapy on the patient's postoperative state anxiety, pain control, and environmental noise satisfaction.

    PubMed

    Comeaux, Tressa; Comeaux, Tressa

    2013-01-01

    Postoperative pain is difficult to manage with analgesia alone. Complementary interventions such as music therapy provide a level of distraction, thus promoting comfort. In this study, decreased pain and environmental noise were demonstrated, without diminishing state anxiety, in a group of postoperative patients.

  7. Masks in Pedagogical Practice

    ERIC Educational Resources Information Center

    Roy, David

    2016-01-01

    In Drama Education mask work is undertaken and presented as both a methodology and knowledge base. There are numerous workshops and journal articles available for teachers that offer knowledge or implementation of mask work. However, empirical examination of the context or potential implementation of masks as a pedagogical tool remains…

  8. Keeping African Masks Real

    ERIC Educational Resources Information Center

    Waddington, Susan

    2012-01-01

    Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…

  9. Computer models for masked hearing experiments with beluga whales (Delphinapterus leucas).

    PubMed

    Erbe, C; King, A R; Yedlin, M; Farmer, D M

    1999-05-01

    Environmental assessments of manmade noise and its effects on marine mammals need to address the question of how noise interferes with animal vocalizations. Seeking the answer with animal experiments is very time consuming, costly, and often infeasible. This article examines the possibility of estimating results with software models. A matched filter, spectrogram cross-correlation, critical band cross-correlation, and a back-propagation neural network detected a beluga vocalization in three types of ocean noise. Performance was compared to masked hearing experiments with a beluga whale [C. Erbe and D. M. Farmer, Deep-Sea Res. II 45, 1373-1388 (1998)]. The artificial neural network simulated the animal data most closely and raised confidence in its ability to predict the interference of a variety of noise source with a variety of vocalizations.

  10. An Effective, Economical Method of Reducing Environmental Noise in the Vivarium

    PubMed Central

    Young, Maggie T; French, Alan L; Clymer, Jeffrey W

    2011-01-01

    High levels of ambient noise can have detrimental effects on laboratory animal wellbeing and may affect experimental results. In addition, excessive noise can reduce technician comfort and performance. This study was performed to determine whether inexpensive, passive acoustic noise abatement measures could meaningfully reduce noise levels. Sound level measurements for various activities were obtained in the incoming processing room for pigs before and after installing gypsum acoustic paneling, covering metal-to-metal contact points with strips of adhesive-backed rubber, and replacing hard plastic wheels on transport carts with neoprene wheels. The modifications reduced the overall average noise level by 8.1 dB. Average noise levels for each activity were all less than 85 dB after the modifications. Average noise levels can be reduced effectively and economically with passive abatement methods. Intermittent spikes in noise are more difficult to control and may require attention to the individual activity. PMID:21838981

  11. An effective, economical method of reducing environmental noise in the vivarium.

    PubMed

    Young, Maggie T; French, Alan L; Clymer, Jeffrey W

    2011-07-01

    High levels of ambient noise can have detrimental effects on laboratory animal wellbeing and may affect experimental results. In addition, excessive noise can reduce technician comfort and performance. This study was performed to determine whether inexpensive, passive acoustic noise abatement measures could meaningfully reduce noise levels. Sound level measurements for various activities were obtained in the incoming processing room for pigs before and after installing gypsum acoustic paneling, covering metal-to-metal contact points with strips of adhesive-backed rubber, and replacing hard plastic wheels on transport carts with neoprene wheels. The modifications reduced the overall average noise level by 8.1 dB. Average noise levels for each activity were all less than 85 dB after the modifications. Average noise levels can be reduced effectively and economically with passive abatement methods. Intermittent spikes in noise are more difficult to control and may require attention to the individual activity.

  12. Forward masking of faces by spatially quantized random and structured masks: on the roles of wholistic configuration, local features, and spatial-frequency spectra in perceptual identification.

    PubMed

    Bachmann, Talis; Luiga, Iiris; Põder, Endel

    2004-12-01

    The forward masking of faces by spatially quantized masking images was studied. Masks were used in order to exert different types of degrading effects on the early representations in facial information processing. Three types of source images for masks were used: Same-face images (with regard to targets), different-face images, and random Gaussian noise that was spectrally similar to facial images. They were all spatially quantized over the same range of quantization values. Same-face masks had virtually no masking effect at any of the quantization values. Different-face masks had strong masking effects only with fine-scale quantization, but led to the same efficiency of recognition as in the same-face mask condition with the coarsest quantization. Moreover, compared with the noise-mask condition, coarsely quantized different-face masks led to a relatively facilitated level of recognition efficiency. The masking effect of the noise mask did not vary significantly with the coarseness of quantization. The results supported neither a local feature processing account, nor a generalized spatial-frequency processing account, but were consistent with the microgenetic configuration-processing theory of face recognition. Also, the suitability of a spatial quantization technique for image configuration processing research has been demonstrated.

  13. Mask degradation monitoring with aerial mask inspector

    NASA Astrophysics Data System (ADS)

    Tseng, Wen-Jui; Fu, Yung-Ying; Lu, Shih-Ping; Jiang, Ming-Sian; Lin, Jeffrey; Wu, Clare; Lifschitz, Sivan; Tam, Aviram

    2013-06-01

    As design rule continues to shrink, microlithography is becoming more challenging and the photomasks need to comply with high scanner laser energy, low CDU, and ever more aggressive RETs. This give rise to numerous challenges in the semiconductor wafer fabrication plants. Some of these challenges being contamination (mainly haze and particles), mask pattern degradation (MoSi oxidation, chrome migration, etc.) and pellicle degradation. Fabs are constantly working to establish an efficient methodology to manage these challenges mainly using mask inspection, wafer inspection, SEM review and CD SEMs. Aerial technology offers a unique opportunity to address the above mask related challenges using one tool. The Applied Materials Aera3TM system has the inherent ability to inspect for defects (haze, particles, etc.), and track mask degradation (e.g. CDU). This paper focuses on haze monitoring, which is still a significant challenge in semiconductor manufacturing, and mask degradation effects that are starting to emerge as the next challenge for high volume semiconductor manufacturers. The paper describes Aerial inspector (Aera3) early haze methodology and mask degradation tracking related to high volume manufacturing. These will be demonstrated on memory products. At the end of the paper we take a brief look on subsequent work currently conducted on the more general issue of photo mask degradation monitoring by means of an Aerial inspector.

  14. Bats perceptually weight prey cues across sensory systems when hunting in noise.

    PubMed

    Gomes, D G E; Page, R A; Geipel, I; Taylor, R C; Ryan, M J; Halfwerk, W

    2016-09-16

    Anthropogenic noise can interfere with environmental information processing and thereby reduce survival and reproduction. Receivers of signals and cues in particular depend on perceptual strategies to adjust to noisy conditions. We found that predators that hunt using prey sounds can reduce the negative impact of noise by making use of prey cues conveyed through additional sensory systems. In the presence of masking noise, but not in its absence, frog-eating bats preferred and were faster in attacking a robotic frog emitting multiple sensory cues. The behavioral changes induced by masking noise were accompanied by an increase in active localization through echolocation. Our findings help to reveal how animals can adapt to anthropogenic noise and have implications for the role of sensory ecology in driving species interactions.

  15. Masking in three pinnipeds: underwater, low-frequency critical ratios.

    PubMed

    Southall, B L; Schusterman, R J; Kastak, D

    2000-09-01

    Behavioral techniques were used to determine underwater masked hearing thresholds for a northern elephant seal (Mirounga angustirostris), a harbor seal (Phoca vitulina), and a California sea lion (Zalophus californianus). Octave-band white noise maskers were centered at five test frequencies ranging from 200 to 2500 Hz; a slightly wider noise band was used for testing at 100 Hz. Critical ratios were calculated at one masking noise level for each test frequency. Above 200 Hz, critical ratios increased with frequency. This pattern is similar to that observed in most animals tested, and indicates that these pinnipeds lack specializations for detecting low-frequency tonal sounds in noise. However, the individual pinnipeds in this study, particularly the northern elephant seal, detected signals at relatively low signal-to-noise ratios. These results provide a means of estimating zones of auditory masking for pinnipeds exposed to anthropogenic noise sources.

  16. The Sensitivity of Coded Mask Telescopes

    NASA Technical Reports Server (NTRS)

    Skinner, Gerald K.

    2008-01-01

    Simple formulae are often used to estimate the sensitivity of coded mask X-ray or gamma-ray telescopes, but t,hese are strictly only applicable if a number of basic assumptions are met. Complications arise, for example, if a grid structure is used to support the mask elements, if the detector spatial resolution is not good enough to completely resolve all the detail in the shadow of the mask or if any of a number of other simplifying conditions are not fulfilled. We derive more general expressions for the Poisson-noise-limited sensitivity of astronomical telescopes using the coded mask technique, noting explicitly in what circumstances they are applicable. The emphasis is on using nomenclature and techniques that result in simple and revealing results. Where no convenient expression is available a procedure is given which allows the calculation of the sensitivity. We consider certain aspects of the optimisation of the design of a coded mask telescope and show that when the detector spatial resolution and the mask to detector separation are fixed, the best source location accuracy is obtained when the mask elements are equal in size to the detector pixels.

  17. 2013 mask industry survey

    NASA Astrophysics Data System (ADS)

    Malloy, Matt

    2013-09-01

    A comprehensive survey was sent to merchant and captive mask shops to gather information about the mask industry as an objective assessment of its overall condition. 2013 marks the 12th consecutive year for this process. Historical topics including general mask profile, mask processing, data and write time, yield and yield loss, delivery times, maintenance, and returns were included and new topics were added. Within each category are multiple questions that result in a detailed profile of both the business and technical status of the mask industry. While each year's survey includes minor updates based on feedback from past years and the need to collect additional data on key topics, the bulk of the survey and reporting structure have remained relatively constant. A series of improvements is being phased in beginning in 2013 to add value to a wider audience, while at the same time retaining the historical content required for trend analyses of the traditional metrics. Additions in 2013 include topics such as top challenges, future concerns, and additional details in key aspects of mask masking, such as the number of masks per mask set per ground rule, minimum mask resolution shipped, and yield by ground rule. These expansions beyond the historical topics are aimed at identifying common issues, gaps, and needs. They will also provide a better understanding of real-life mask requirements and capabilities for comparison to the International Technology Roadmap for Semiconductors (ITRS).

  18. Assessing residential exposure to urban noise using environmental models: does the size of the local living neighborhood matter?

    PubMed

    Tenailleau, Quentin M; Bernard, Nadine; Pujol, Sophie; Houot, Hélène; Joly, Daniel; Mauny, Frédéric

    2015-01-01

    Environmental epidemiological studies rely on the quantification of the exposure level in a surface defined as the subject's exposure area. For residential exposure, this area is often the subject's neighborhood. However, the variability of the size and nature of the neighborhoods makes comparison of the findings across studies difficult. This article examines the impact of the neighborhood's definition on environmental noise exposure levels obtained from four commonly used sampling techniques: address point, façade, buffers, and official zoning. A high-definition noise model, built on a middle-sized French city, has been used to estimate LAeq,24 h exposure in the vicinity of 10,825 residential buildings. Twelve noise exposure indicators have been used to assess inhabitants' exposure. Influence of urban environmental factors was analyzed using multilevel modeling. When the sampled area increases, the average exposure increases (+3.9 dB), whereas the SD decreases (-1.6 dB) (P<0.01). Most of the indicators differ statistically. When comparing indicators from the 50-m and 400-m radius buffers, the assigned LAeq,24 h level varies across buildings from -9.4 to +22.3 dB. This variation is influenced by urban environmental characteristics (P<0.01). On the basis of this study's findings, sampling technique, neighborhood size, and environmental composition should be carefully considered in further exposure studies.

  19. Analyzing EUV mask costs

    NASA Astrophysics Data System (ADS)

    Lercel, Michael; Kasprowicz, Bryan

    2016-10-01

    The introduction of Extreme Ultraviolet Lithography (EUV) as a replacement for multiple patterning is based on improvements of cycle time, yield, and cost. Earlier cost studies have assumed a simple assumption that EUV masks (being more complex with the multilayer coated blank) are not more than three times as expensive as advanced ArFi (ArF immersion) masks. EUV masks are expected to be more expensive during the ramp of the technology because of the added cost of the complex mask blank, the use of EUV specific mask tools, and a ramp of yield learning relative to the more mature technologies. This study concludes that, within a range of scenarios, the hypothesis that EUV mask costs are not more than three times that of advanced ArFi masks is valid and conservative.

  20. Protecting a quantum state from environmental noise by an incompatible finite-time measurement

    SciTech Connect

    Brasil, Carlos Alexandre; Castro, L. A. de; Napolitano, R. d. J.

    2011-08-15

    We show that measurements of finite duration performed on an open two-state system can protect the initial state from a phase-noisy environment, provided the measured observable does not commute with the perturbing interaction. When the measured observable commutes with the environmental interaction, the finite-duration measurement accelerates the rate of decoherence induced by the phase noise. For the description of the measurement of an observable that is incompatible with the interaction between system and environment, we have found an approximate analytical expression, valid at zero temperature and weak coupling with the measuring device. We have tested the validity of the analytical predictions against an exact numerical approach, based on the superoperator-splitting method, that confirms the protection of the initial state of the system. When the coupling between the system and the measuring apparatus increases beyond the range of validity of the analytical approximation, the initial state is still protected by the finite-time measurement, according with the exact numerical calculations.

  1. Environmental noise effects on entanglement fidelity of exchange-coupled semiconductor spin qubits

    NASA Astrophysics Data System (ADS)

    Throckmorton, Robert E.; Barnes, Edwin; Das Sarma, S.

    2017-02-01

    We investigate the effect of magnetic field and charge noise on the generation of entanglement between two Heisenberg exchange-coupled electron spins in a double quantum dot. We focus on exchange-driven evolution that would ideally take an initial unentangled tensor product state to a maximally entangled state in the absence of noise. The presence of noise obviously adversely affects the attainment of maximal entanglement, which we study quantitatively and exactly. To quantify the effects of noise, we calculate two-qubit coherence times and entanglement fidelity, both of which can be extracted from simulations or measurements of the return probability as a function of interaction time, i.e., the time period during which the exchange coupling remains effective between the two spins. We perform these calculations for a broad range of noise strengths that includes the regime of recent experiments. We find that the two types of noise reduce the amount of entanglement in qualitatively distinct ways and that, although charge noise generally leads to faster decoherence, the relative importance of the two types of noise in entanglement creation depends sensitively on the strength of the exchange coupling. Our results can be used to determine the level of noise suppression needed to reach quantum error correction thresholds. We provide quantitative guidance for the requisite noise constraints necessary to eventually reach the >99 % fidelity consistent with the quantum error correction threshold.

  2. Little effect of natural noise on high-frequency hearing in frogs, Odorrana tormota.

    PubMed

    Liu, Jing; Yang, Han; Hu, Guang-Lei; Li, Shan; Xu, Zhi-Min; Qi, Zhi; Shen, Jun-Xian

    2015-10-01

    Ambient noise influences acoustic communication in animals. The concave-eared frogs (Odorrana tormota) produce high-frequency sound signals to avoid potential masking from noise. However, whether environmental noise has effect on the high-frequency hearing of frogs is largely unclear. By measuring the auditory evoked near-field potentials (AENFPs) from the torus semicircularis of the midbrain at frequencies 1-23 kHz in the presence of three noise levels, we found no significant difference in the peak-to-peak amplitude, threshold and latency of AENFP between low-level (35 dB SPL) background noise and mid-level (65 dB SPL) broadcast natural noise. For a natural noise level of 85 dB SPL, AENFP amplitude decreased and threshold and latency increased at frequencies 3-13 kHz. Spike counts evoked by stimuli at the best excitatory frequency under 85 dB SPL natural noise exposure were lower in 7-kHz CF neurons than in exposures to 35 and 65 dB SPL noise. However spike counts were similar for 14- and 20-kHz CF neurons at the three exposure levels. These findings indicate that environmental noise does not mask the responses of high-frequency tuned auditory neurons, and suggest that the acoustic communication system of O. tormota is efficiently adapted to noisy habitats.

  3. Speech communications in noise

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The physical characteristics of speech, the methods of speech masking measurement, and the effects of noise on speech communication are investigated. Topics include the speech signal and intelligibility, the effects of noise on intelligibility, the articulation index, and various devices for evaluating speech systems.

  4. Speech communications in noise

    NASA Astrophysics Data System (ADS)

    1984-07-01

    The physical characteristics of speech, the methods of speech masking measurement, and the effects of noise on speech communication are investigated. Topics include the speech signal and intelligibility, the effects of noise on intelligibility, the articulation index, and various devices for evaluating speech systems.

  5. High quality mask storage in an advanced Logic-Fab

    NASA Astrophysics Data System (ADS)

    Jähnert, Carmen; Fritsche, Silvio

    2012-02-01

    High efficient mask logistics as well as safe and high quality mask storage are essential requirements within an advanced lithography area of a modern logic waferfab. Fast operational availability of the required masks at the exposure tool with excellent mask condition requires a safe mask handling, safeguarding of high mask quality over the whole mask usage time without any quality degradation and an intelligent mask logistics. One big challenge is the prevention of haze on high advanced phase shift masks used in a high volume production line for some thousands of 248nm or 193nm exposures. In 2008 Infineon Dresden qualified a customer specific developed semi-bare mask storage system from DMSDynamic Micro Systems in combination with a high advanced mask handling and an interconnected complex logistic system. This high-capacity mask storage system DMS M1900.22 for more than 3000 masks with fully automated mask and box handling as well as full-blown XCDA purge has been developed and adapted to the Infineon Lithotoollandscape using Nikon and SMIF reticle cases. Advanced features for ESD safety and mask security, mask tracking via RFID and interactions with the exposure tools were developed and implemented. The stocker is remote controlled by the iCADA-RSM system, ordering of the requested mask directly from the affected exposure tool allows fast access. This paper discusses the advantages and challenges for this approach as well as the practical experience gained during the implementation of the new system which improves the fab performance with respect to mask quality, security and throughput. Especially the realization of an extremely low and stable humidity level in addition with a well controlled air flow at each mask surface, preventing masks from haze degradation and particle contamination, turns out to be a notable technical achievement. The longterm stability of haze critical masks has been improved significantly. Relevant environmental parameters like

  6. Noise-induced hearing loss in children: A ‘less than silent’ environmental danger

    PubMed Central

    Harrison, Robert V

    2008-01-01

    A review of the problems of noise-induced hearing loss in children, especially related to recreational music and the use of personal entertainment devices. The pathophysiology of noise-induced hearing loss and its associated problems (eg, tinnitus) are discussed. The evidence for an increase in noise-induced hearing loss in children and young people is reviewed. Some practical advice (for clinicians, caregivers and children) on hearing loss prevention is provided. PMID:19412364

  7. Investigation of EUV haze defect: molecular behaviors of mask cleaning chemicals on EUV mask surfaces

    NASA Astrophysics Data System (ADS)

    Choi, Jaehyuck; Novak, Steve; Kandel, Yudhishthir; Denbeaux, Greg; Lee, Han-shin; Ma, Andy; Goodwin, Frank

    2012-03-01

    Photo-induced defects (or haze defects) on 193nm optic masks (haze defects) have been a serious problem not only to reticle engineers working for mask manufacturing and handling but also to photo-lithography engineers. The most widely accepted explanation of the root causes of haze defects is the cleaning chemical residues remaining on the mask surface and unavoidable outgassed molecules that outgas from pellicle materials when exposed to 193nm radiation. These have been significant challenges for reticle cleaning engineers who need to use cleaning chemicals whose residues do not lead to progressive defect formation on the mask and to find improved materials to minimize pellicle outgassing. It is assumed that contamination generation on EUV masks would have a higher probability than on optic masks, primarily since EUV masks are not protected by a pellicle and amorphous carbon films can accumulate during exposure to EUV light. While there is potential to mitigate the generation of carbon contamination by improving the exposure tool environment and removing carbon films using in-situ atomic hydrogen cleaning, it is not yet clear whether the reaction of mask cleaning chemicals to EUV radiation will lead to creation of progressive defects on EUV mask surfaces. With the work to being done it has been observed that carbon contamination on EUV masks dominates any effects of solvent chemicals under normal environmental or exposure conditions (from atmospheric pressure up to a vacuum level of 10-6 Torr) during EUV exposure. However, it is still unknown whether residual cleaning chemicals will provide a nucleus for progressive defect formation during exposure. This lack of understanding needs to be addressed by the industry as EUV masks are expected to undergo more frequent cleaning cycles. In this work, we will report on an investigation of the molecular behavior of cleaning chemicals on EUV mask surfaces during EUV exposure. Movement (e.g., migration or aggregation) of

  8. Perspectives on noise in the menu of environmental issues, and the role of technical solutions relative to policy approaches

    NASA Astrophysics Data System (ADS)

    Burleson, Carl

    2005-09-01

    Over the last thirty years, the number of people affected by aircraft noise has decreased while air travel has grown dramatically. Despite this success, environmental issues, both noise and emissions, may become the key constraint on future air transportation expansion. As part of the Next Generation Air Transportation System Plan, the goal is for environmental protection that allows for sustained aviation growth. This includes reductions, in absolute terms, of community noise and local air quality emissions from aviation that significantly impact human health and welfare. Achieving these goals will require a multi-pronged approach that combines source reduction technology, operational abatement procedures, intelligent land use planning, and airport and aircraft operating restrictions. Given the interdependencies of impacts, there is a need to move from stand-alone models to an integrated tool set that allows understanding of the interactions between noise, air quality, economic costs and benefits. Such models would enable more effective evaluation of proposed air transportation system changes and allow communities and decision-makers better information to reach decisions on the proposed changes. FAA has initiated a multi-year, multi-million dollar effort to develop these models and improved capabilities and decision-making that will aid in tackling the enviornnmental challenges of aviation growth.

  9. Mask industry assessment: 2003

    NASA Astrophysics Data System (ADS)

    Kimmel, Kurt R.

    2003-12-01

    Microelectronics industry leaders routinely name mask technology and mask supply issues of cost and cycle time as top issues of concern. A survey was initiated in 2002 with support from International SEMATECH (ISMT) and administered by SEMI North America to gather information about the mask industry as an objective assessment of its overall condition.1 This paper presents the results of the second annual survey which is an enhanced version of the inaugural survey building upon its strengths and improving the weak points. The original survey was designed with the input of member company mask technologists, merchant mask suppliers, and industry equipment makers. The assessment is intended to be used as a baseline for the mask industry and the microelectronics industry to gain a perspective on the technical and business status of the critical mask industry. An objective is to create a valuable reference to identify strengths and opportunities and to guide investments on critical-path issues. As subsequent years are added, historical profiles can also be created. This assessment includes inputs from ten major global merchant and captive mask manufacturers representing approximately 80% of the global mask market (using revenue as the measure) and making this the most comprehensive mask industry survey ever. The participating companies are: Compugraphics, Dai Nippon Printing, Dupont Photomask, Hoya, IBM, Infineon, Intel, Taiwan Mask Company, Toppan, and TSMC. Questions are grouped into five categories: General Business Profile Information; Data Processing; Yields and Yield loss Mechanisms; Delivery Time; and Returns and Services. Within each category are a multitude of questions that create a detailed profile of both the business and technical status of the mask industry.

  10. Object Substitution Masking: When Does Mask Preview Work?

    ERIC Educational Resources Information Center

    Lim, Stephen Wee Hun; Chua, Fook K.

    2008-01-01

    When a target is enclosed by a 4-dot mask that persists after the target disappears, target identification is worse than it is when the mask terminates with the target. This masking effect is attributed to object substitution masking (OSM). Previewing the mask, however, attenuates OSM. This study investigated specific conditions under which mask…

  11. Progress of Aircraft System Noise Assessment with Uncertainty Quantification for the Environmentally Responsible Aviation Project

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Burley, Casey L.; Guo, Yueping

    2016-01-01

    Aircraft system noise predictions have been performed for NASA modeled hybrid wing body aircraft advanced concepts with 2025 entry-into-service technology assumptions. The system noise predictions developed over a period from 2009 to 2016 as a result of improved modeling of the aircraft concepts, design changes, technology development, flight path modeling, and the use of extensive integrated system level experimental data. In addition, the system noise prediction models and process have been improved in many ways. An additional process is developed here for quantifying the uncertainty with a 95% confidence level. This uncertainty applies only to the aircraft system noise prediction process. For three points in time during this period, the vehicle designs, technologies, and noise prediction process are documented. For each of the three predictions, and with the information available at each of those points in time, the uncertainty is quantified using the direct Monte Carlo method with 10,000 simulations. For the prediction of cumulative noise of an advanced aircraft at the conceptual level of design, the total uncertainty band has been reduced from 12.2 to 9.6 EPNL dB. A value of 3.6 EPNL dB is proposed as the lower limit of uncertainty possible for the cumulative system noise prediction of an advanced aircraft concept.

  12. Cumulative effects of noise and odour annoyances on environmental and health related quality of life.

    PubMed

    Oiamo, Tor H; Luginaah, Isaac N; Baxter, Jamie

    2015-12-01

    Noise and odour annoyances are important considerations in research on health effects of air pollution and traffic noise. Cumulative exposures can occur via several chemical hazards or a combination of chemical and stressor-based hazards, and related health outcomes can be generalized as manifestations of physiological and/or psychological stress responses. A major research challenge in this field is to understand the combined health effects of physiological and psychological responses to exposure. The SF-12 Health Survey is a health related quality of life (HRQoL) instrument designed for the assessment of functional mental and physical health in clinical practice and therefore well suited to research on physiological health outcomes of exposure. However, previous research has not assessed its sensitivity to psychological stress as measured by noise annoyance and odour annoyance. The current study validated and tested this application of the SF-12 Health Survey in a cross-sectional study (n = 603) that included exposure assessment for traffic noise and air pollution in Windsor, Ontario, Canada. The results indicated that SF-12 scores in Windsor were lower than Canadian normative data. A structural equation model demonstrated that this was partially due to noise and odour annoyances, which were associated with covarying exposures to ambient nitrogen dioxide and traffic noise. More specifically, noise annoyance had a significant and negative effect on both mental and physical health factors of the SF-12 and there was a significant covariance between noise annoyance and odour annoyance. The study confirmed a significant effect of psychological responses to cumulative exposures on HRQoL. The SF-12 Health Survey shows promise with respect to assessing the cumulative health effects of outdoor air pollution and traffic noise.

  13. Anthropogenic noise disrupts use of vocal information about predation risk.

    PubMed

    Kern, Julie M; Radford, Andrew N

    2016-11-01

    Anthropogenic noise is rapidly becoming a universal environmental feature. While the impacts of such additional noise on avian sexual signals are well documented, our understanding of its effect in other terrestrial taxa, on other vocalisations, and on receivers is more limited. Little is known, for example, about the influence of anthropogenic noise on responses to vocalisations relating to predation risk, despite the potential fitness consequences. We use playback experiments to investigate the impact of traffic noise on the responses of foraging dwarf mongooses (Helogale parvula) to surveillance calls produced by sentinels, individuals scanning for danger from a raised position whose presence usually results in reduced vigilance by foragers. Foragers exhibited a lessened response to surveillance calls in traffic-noise compared to ambient-sound playback, increasing personal vigilance. A second playback experiment, using noise playbacks without surveillance calls, suggests that the increased vigilance could arise in part from the direct influence of additional noise as there was an increase in response to traffic-noise playback alone. Acoustic masking could also play a role. Foragers maintained the ability to distinguish between sentinels of different dominance class, increasing personal vigilance when presented with subordinate surveillance calls compared to calls of a dominant groupmate in both noise treatments, suggesting complete masking was not occurring. However, an acoustic-transmission experiment showed that while surveillance calls were potentially audible during approaching traffic noise, they were probably inaudible during peak traffic intensity noise. While recent work has demonstrated detrimental effects of anthropogenic noise on defensive responses to actual predatory attacks, which are relatively rare, our results provide evidence of a potentially more widespread influence since animals should constantly assess background risk to optimise the

  14. Enhancement in Informational Masking

    ERIC Educational Resources Information Center

    Cao, Xiang; Richards, Virginia M.

    2012-01-01

    Purpose: The ability to detect a tone added to a random masker improves when a preview of the masker is provided. In 2 experiments, the authors explored the role that perceptual organization plays in this release from masking. Method: Detection thresholds were measured in informational masking studies. The maskers were drawn at random prior to…

  15. Lightweight Face Mask

    NASA Technical Reports Server (NTRS)

    Cason, W. E. I.; Baucom, R. M.; Evans, R. C.

    1982-01-01

    Lightweight face mask originally developed to protect epileptic patients during seizures could have many other medical and nonmedical applications such as muscular distrophy patients, football linesmen and riot-control police. Masks are extremely lightweight, the lightest of the configurations weighing only 136 grams.

  16. Analysis of Measured Environmental Noise Levels: An Assessment of the Effects of Airbase Operational Model Variables on Predicted Noise Exposure Levels

    DTIC Science & Technology

    1991-06-01

    measured noise data was used in an effort to quantify the complicating factors relevant to airbase enviromental noise prediction. These factors are...were used to optimize the operational profiles influencing the noise predictions at that location. Some marginal benefit from this effort was realized...Records The McChord measured noise data was originally recorded on printed paper tapes. The measured noise events’ data were entered into the

  17. EBM-9000: EB mask writer for product mask fabrication of 16nm half-pitch generation and beyond

    NASA Astrophysics Data System (ADS)

    Takekoshi, Hidekazu; Nakayama, Takahito; Saito, Kenichi; Ando, Hiroyoshi; Inoue, Hideo; Nakayamada, Noriaki; Kamikubo, Takashi; Nishimura, Rieko; Kojima, Yoshinori; Yashima, Jun; Anpo, Akihito; Nakazawa, Seiichi; Iijima, Tomohiro; Ohtoshi, Kenji; Anze, Hirohito; Katsap, Victor; Golladay, Steven; Kendall, Rodney

    2014-10-01

    In the half pitch (hp) 16nm generation, the shot count on a mask is expected to become bipolar. The multi-patterning technology in lithography seems to maintain the shot count around 300G shots instead of increase in the number of masks needed for one layer. However, as a result of mask multiplication, the better positional accuracy would be required especially in Mask-to-Mask overlay. On the other hand, in complex OPC, the shot count on a mask is expected to exceed 1T shots. In addition, regardless of the shot count forecast, the resist sensitivity needs to be lower to reduce the shot noise effect so as to get better LER. In other words, slow resist would appear on main stream, in near future. Hence, such trend would result in longer write time than that of the previous generations. At the same time, most mask makers request masks to be written within 24 hours. Thus, a faster mask writer with better writing accuracy than those of previous generations is needed. With this background, a new electron beam mask writing system, EBM- 9000, has been developed to satisfy such requirements of the hp 16nm generation. The development of EBM-9000 has focused on improving throughput for larger shot counts and improving the writing accuracy.

  18. Diagnostic System Based on the Human AUDITORY-BRAIN Model for Measuring Environmental NOISE—AN Application to Railway Noise

    NASA Astrophysics Data System (ADS)

    SAKAI, H.; HOTEHAMA, T.; ANDO, Y.; PRODI, N.; POMPOLI, R.

    2002-02-01

    Measurements of railway noise were conducted by use of a diagnostic system of regional environmental noise. The system is based on the model of the human auditory-brain system. The model consists of the interplay of autocorrelators and an interaural crosscorrelator acting on the pressure signals arriving at the ear entrances, and takes into account the specialization of left and right human cerebral hemispheres. Different kinds of railway noise were measured through binaural microphones of a dummy head. To characterize the railway noise, physical factors, extracted from the autocorrelation functions (ACF) and interaural crosscorrelation function (IACF) of binaural signals, were used. The factors extracted from ACF were (1) energy represented at the origin of the delay, Φ (0), (2) effective duration of the envelope of the normalized ACF, τe, (3) the delay time of the first peak, τ1, and (4) its amplitude,ø1 . The factors extracted from IACF were (5) IACC, (6) interaural delay time at which the IACC is defined, τIACC, and (7) width of the IACF at the τIACC,WIACC . The factor Φ (0) can be represented as a geometrical mean of energies at both ears as listening level, LL.

  19. Wavelet speech enhancement algorithm using exponential semi-soft mask filtering.

    PubMed

    Lee, Gihyoun; Dae Na, Sung; Seong, KiWoong; Cho, Jin-Ho; Nam Kim, Myoung

    2016-09-02

    In this paper, we propose a new speech enhancement algorithm based on wavelet packet decomposition and mask filtering. In the traditional mask filtering such as ideal binary mask (IBM), the basic idea is to classify speech components as target signal and non-speech components as background noises. However, speech and non-speech components cannot be well separated in target signal and background noise. Therefore, the IBM has residual noise and signal loss. To overcome this problem, the proposed algorithm used semi-soft mask filter to exponentially increase. The semi-soft mask minimizes signal loss and the exponential filter removes residual noise. We performed experiments using various types of speech and noise signals, and experimental results show that the proposed algorithm achieves better performances than the traditional other speech enhancement algorithms.

  20. Self-masking: Listening during vocalization. Normal hearing.

    PubMed

    Borg, Erik; Bergkvist, Christina; Gustafsson, Dan

    2009-06-01

    What underlying mechanisms are involved in the ability to talk and listen simultaneously and what role does self-masking play under conditions of hearing impairment? The purpose of the present series of studies is to describe a technique for assessment of masked thresholds during vocalization, to describe normative data for males and females, and to focus on hearing impairment. The masking effect of vocalized [a:] on narrow-band noise pulses (250-8000 Hz) was studied using the maximum vocalization method. An amplitude-modulated series of sound pulses, which sounded like a steam engine, was masked until the criterion of halving the perceived pulse rate was reached. For masking of continuous reading, a just-follow-conversation criterion was applied. Intra-session test-retest reproducibility and inter-session variability were calculated. The results showed that female voices were more efficient in masking high frequency noise bursts than male voices and more efficient in masking both a male and a female test reading. The male had to vocalize 4 dBA louder than the female to produce the same masking effect on the test reading. It is concluded that the method is relatively simple to apply and has small intra-session and fair inter-session variability. Interesting gender differences were observed.

  1. 2012 Mask Industry Survey

    NASA Astrophysics Data System (ADS)

    Malloy, Matt; Litt, Lloyd C.

    2012-11-01

    A survey supported by SEMATECH and administered by David Powell Consulting was sent to semiconductor industry leaders to gather information about the mask industry as an objective assessment of its overall condition. The survey was designed with the input of semiconductor company mask technologists and merchant mask suppliers. 2012 marks the 11th consecutive year for the mask industry survey. This year's survey and reporting structure are similar to those of the previous years with minor modifications based on feedback from past years and the need to collect additional data on key topics. Categories include general mask information, mask processing, data and write time, yield and yield loss, delivery times, and maintenance and returns. Within each category are multiple questions that result in a detailed profile of both the business and technical status of the mask industry. Results, initial observations, and key comparisons between the 2011 and 2012 survey responses are shown here, including multiple indications of a shift towards the manufacturing of higher end photomasks.

  2. Special assessment of aircraft noise effects during night by the Council of Experts for Environmental Questions of FRG.

    PubMed

    Scheuch, K

    2004-01-01

    The "Special Assessment of Environment and Health" (SAEH) by the Council of Experts for Environmental Questions of Federal Republic of Germany is presented regarding to it's statements concerning the consequences of aircraft noise during night. Considering the issue of sustainability it is emphasized that lower limit values of the validity of scientific results need to be accepted. As the discussion of the literature shows the statements of the Council are rather vague and warily. This is a question of used parameters of noise effects during the night as well as its interpretation. It seems necessary to utilize a hierarchical structure of limit values and with interpretation of the term "threshold" as normal physiological reactions. More investigations are necessary in this field.

  3. Noise Protection

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Environmental Health Systems puts forth an increasing effort in the U.S. to develop ways of controlling noise, particularly in industrial environments due to Federal and State laws, labor union insistence and new findings relative to noise pollution impact on human health. NASA's Apollo guidance control system aided in the development of a noise protection product, SMART. The basis of all SMART products is SMART compound a liquid plastic mixture with exceptional energy/sound absorbing qualities. The basic compound was later refined for noise protection use.

  4. Influence of masker bandwidth on binaural masking level differences.

    PubMed

    Harris, R W; Brey, R H; Miller, R W; Channell, R W

    1992-01-01

    Masking level differences (MLDs) were investigated using masking noise with 160 Hz (amplitude-modulated noise) and 600 Hz (filtered-random noise) bandwidth. One hundred normally hearing subjects received the MLD test under both types of noise. Significant differences between noise types were observed in both N0S pi and N pi S0 conditions; MLDs were larger in amplitude-modulated noise. Consideration of these differences would indicate that older MLD norms based solely on filtered-random noise are invalid for amplitude-modulated noise especially where bandwidth differences in the noise exist. Were the norms for 600-Hz-wide filtered-random noise to be applied to results of MLD testing performed using 160-Hz-wide amplitude-modulated noise, patients with lesions in the central auditory pathway might exhibit normal or borderline normal results. Clinical MLD norms established on one type of noise should not be used to interpret MLD results obtained using a different type of noise.

  5. National Environmental/Energy Workforce Assessment, Phase II, Post-Secondary Education Profile: Noise.

    ERIC Educational Resources Information Center

    National Field Research Center Inc., Iowa City, IA.

    Noise-related training programs were reviewed in nine degree-granting institutions in seven states. These programs represent a sample, only, of the various programs available nationwide. The enrollment profile and average number of graduates by degree level for the past three years are given, as well as the apparent enrollment trends by degree…

  6. The subjective importance of noise spectral content

    NASA Astrophysics Data System (ADS)

    Baxter, Donald; Phillips, Jonathan; Denman, Hugh

    2014-01-01

    This paper presents secondary Standard Quality Scale (SQS2) rankings in overall quality JNDs for a subjective analysis of the 3 axes of noise, amplitude, spectral content, and noise type, based on the ISO 20462 softcopy ruler protocol. For the initial pilot study, a Python noise simulation model was created to generate the matrix of noise masks for the softcopy ruler base images with different levels of noise, different low pass filter noise bandwidths and different band pass filter center frequencies, and 3 different types of noise: luma only, chroma only, and luma and chroma combined. Based on the lessons learned, the full subjective experiment, involving 27 observers from Google, NVIDIA and STMicroelectronics was modified to incorporate a wider set of base image scenes, and the removal of band pass filtered noise masks to ease observer fatigue. Good correlation was observed with the Aptina subjective noise study. The absence of tone mapping in the noise simulation model visibly reduced the contrast at high levels of noise, due to the clipping of the high levels of noise near black and white. Under the 34-inch viewing distance, no significant difference was found between the luma only noise masks and the combined luma and chroma noise masks. This was not the intuitive expectation. Two of the base images with large uniform areas, `restaurant' and `no parking', were found to be consistently more sensitive to noise than the texture rich scenes. Two key conclusions are (1) there are fundamentally different sensitivities to noise on a flat patch versus noise in real images and (2) magnification of an image accentuates visual noise in a way that is non-representative of typical noise reduction algorithms generating the same output frequency. Analysis of our experimental noise masks applied to a synthetic Macbeth ColorChecker Chart confirmed the color-dependent nature of the visibility of luma and chroma noise.

  7. New mask technology challenges

    NASA Astrophysics Data System (ADS)

    Kimmel, Kurt R.

    2001-09-01

    Mask technology development has accelerated dramatically in recent years from the glacial pace of the last three decades to the rapid and sometimes simultaneous introductions of new wavelengths and mask-based resolution enhancement techniques. The nature of the semiconductor business has also become one driven by time-to-market as an overwhelming factor in capturing market share and profit. These are among the factors that have created enormous stress on the mask industry to produce masks with enhanced capabilities, such as phase-shifting attenuators, sub-resolution assist bars, and optical proximity correction (OPC) features, while maintaining or reducing cost and cycle time. The mask can no longer be considered a commodity item that is purchased form the lowest-cost supplier. Instead, it must now be promoted as an integral part of the technical and business case for a total lithographic solution. Improving partnership between designer, mask-maker, and wafer lithographer will be the harbinger of success in finding a profitable balance of capability, cost, and cycle time. Likewise for equipment infrastructure development, stronger partnership on the international level is necessary to control development cost and mitigate schedule and technical risks.

  8. Mask Industry Assessment: 2011

    NASA Astrophysics Data System (ADS)

    Chan, Y. David

    2011-11-01

    A survey supported by SEMATECH and administered by David Powell Consulting was sent to microelectronics industry leaders to gather information about the mask industry as an objective assessment of its overall condition. The survey was designed with the input of semiconductor company mask technologists and merchant mask suppliers. This year's assessment is the tenth in the current series of annual reports. With ongoing industry support, the report has been used as one of the baselines to gain perspective on the technical and business status of the mask and microelectronics industries. It continues to serve as a valuable reference to identify the strengths and opportunities of the mask industry. The results will be used to guide future investments pertaining to critical path issues. This year's survey was essentially the same as the 2005 through 2010 surveys. Questions are grouped into following categories: General Business Profile Information, Data Processing, Yields and Yield Loss Mechanisms, Delivery Times, Returns, and Services. Within each category are multiple questions that result in a detailed profile of both the business and technical status of the critical mask industry. This profile combined with the responses to past surveys represents a comprehensive view of changes in the industry.

  9. Mask Industry Assessment: 2010

    NASA Astrophysics Data System (ADS)

    Hughes, Greg; Chan, David Y.

    2010-09-01

    A survey created supported by SEMATECH and administered by David Powell Consulting was sent to microelectronics industry leaders to gather information about the mask industry as an objective assessment of its overall condition. The survey was designed with the input of semiconductor company mask technologists and merchant mask suppliers. This year's assessment is the ninth in the current series of annual reports. With ongoing industry support, the report can be used as a baseline to gain perspective on the technical and business status of the mask and microelectronics industries. It will continue to serve as a valuable reference to identify the strengths and opportunities of the mask industry. The results will be used to guide future investments pertaining to critical path issues. This year's survey was basically the same as the 2005 through 2009 surveys. Questions are grouped into categories: General Business Profile Information, Data Processing, Yields and Yield Loss Mechanisms, Delivery Times, Returns, and Services. Within each category are multiple questions that result in a detailed profile of both the business and technical status of the critical mask industry. This profile combined with the responses to past surveys represents a comprehensive view of changes in the industry.

  10. Masks: The Artist in Me

    ERIC Educational Resources Information Center

    Skophammer, Karen

    2009-01-01

    Whether masks are made from cardboard, papier-mache, metal, wood, leather, fabric, clay or any combination of these materials, they bring out the artist in people. Young children like to wear masks when they play to pretend they were another person or animal. Masks let them fantasize and be creative. The author's students made masks representing…

  11. Research on lithography based on the digital coding-mask technique

    NASA Astrophysics Data System (ADS)

    Xu, Yanqiang; Luo, Ningning; Zhang, Zhimin; Bai, Lu; Gao, Yiqing

    2016-10-01

    Digital coding-mask technique based on digital micro-mirror devices (DMD) is proposed in this paper. The fundamental rule of digital coding-mask technique is to modulate the incident light intensity by adjusting the transmittance of the units on the coding-mask. The transmittance is controlled by the apertures on the units of the coding-mask. Lohmann's III coding method and error diffusion coding method are employed to coding mask, and wavelet transformation is used to suppress the background noise of the mask image. Real-time control on the image of the digital coding mask can be realized by loading the coded mask image to DMD, which is driven by a computer. Digital coding-mask technique gives full play of the advantages of DMD, such as real time and flexibility. In addition, the digital coding-mask technique is helpful to deal with the problem of mask aberration, which is caused by the nonlinear effect in the process of projection and exposure. This technique can also make use of optimization algorithm to suppress the background noise of the digital coding-mask images so that the quality of the relief structure of photoresist is improved.

  12. Environmental noise characteristics of the MOD5-B (3.2 MW) wind turbine generator

    NASA Technical Reports Server (NTRS)

    Shepherd, Kevin P.; Hubbard, Harvey H.

    1989-01-01

    Both narrow band and broad band acoustic data were obtained for the MOD5-B wind turbine for a range of wind speeds from 5.8 to 14.3 m/s; for a range of power outputs from 300 to 3100 kW; and for various azimuth angles and distances. Comparisons are made with those of other large machines and with predictions by available methods. The highest levels occur at the lower frequencies and generally decrease as the frequency increases. Low frequency rotational noise components were more intense than expected for an upwind machine and are believed to result from localized wind gradients across the rotor disk due to upwind terrain features. Predicted broad band spectra follow the general trends of the data but tend to underestimate the levels in the frequency range where the turbulent boundary layer-trailing edge interaction noise is expected to be significant.

  13. Discrimination of environmental background noise in presence of speech using sample-pairs statistics based features

    NASA Astrophysics Data System (ADS)

    Jhanwar, D.; Sharma, Kamlesh K.; Modani, S. G.

    2015-09-01

    A methodology to discriminate the different classes of background noise using new features based on samples of the signal is presented here. Two consecutive samples of different amplitude of the discretetime signals are termed as sample-pair and 14 types of sample-pairs are considered here as fundamental features. Results of simulation work proves that count of some of such type of sample-pairs as well as count of few combinations of two, three and four such sample-pairs are useful to detect and discriminate the different acoustic noise mixed with speech signals. On the basis of simulation results, the performance of proposed features have proved better than other spectral features like Mel Frequency Cepstral Coefficients (MFCC), Spectral Centroid, Spectral Flux and Spectral Roll-off regarding discrimination capabilities, simplicity of extraction process and lesser dependency over speech utterances mixed with noise. These sample-pairs based features having advantage of not requiring frame-decomposition and silence period removal. Their discrimination capabilities are shown by Fisher's F-ratio as performance index. The multiclass Support Vector Machine (SVM) is used as a classifier.

  14. Implementation of the EU environmental noise directive: lessons from the first phase of strategic noise mapping and action planning in Ireland.

    PubMed

    King, E A; Murphy, E; Rice, H J

    2011-03-01

    The first phase of noise mapping and action planning in Ireland, in accordance with EU Directive 2002/49/EC, is now complete. In total this included one agglomeration, one airport and approximately 600 km of major roads outside the agglomeration. These noise maps describe the level of noise exposure of approximately 1.25 million people. The first phase of noise mapping was dealt with by five noise mapping bodies while 26 action planning authorities were involved in the development of the associated action plans. The second phase of noise mapping, due to be completed in 2012, sees a reduction in the defined thresholds describing the required agglomerations, roads and railways that have to be mapped. This will have a significant impact on the extent of mapping required. In Ireland this will result in an increased number of local authorities being required to develop strategic noise maps for their area along with the further development of associated action plans. It is appropriate at this point to review the work process and results from the first phase of noise mapping in Ireland in order to establish areas that could be improved, throughout the noise mapping project. In this paper a review of the implementation procedures focussing on (dominant) road traffic noise is presented. It is identified that more standardisation is needed and this could be achieved by the establishment of a national expert steering group.

  15. Characterizing large river sounds: Providing context for understanding the environmental effects of noise produced by hydrokinetic turbines.

    PubMed

    Bevelhimer, Mark S; Deng, Z Daniel; Scherelis, Constantin

    2016-01-01

    Underwater noise associated with the installation and operation of hydrokinetic turbines in rivers and tidal zones presents a potential environmental concern for fish and marine mammals. Comparing the spectral quality of sounds emitted by hydrokinetic turbines to natural and other anthropogenic sound sources is an initial step at understanding potential environmental impacts. Underwater recordings were obtained from passing vessels and natural underwater sound sources in static and flowing waters. Static water measurements were taken in a lake with minimal background noise. Flowing water measurements were taken at a previously proposed deployment site for hydrokinetic turbines on the Mississippi River, where sounds created by flowing water are part of all measurements, both natural ambient and anthropogenic sources. Vessel sizes ranged from a small fishing boat with 60 hp outboard motor to an 18-unit barge train being pushed upstream by tugboat. As expected, large vessels with large engines created the highest sound levels, which were, on average, 40 dB greater than the sound created by an operating hydrokinetic turbine. A comparison of sound levels from the same sources at different distances using both spherical and cylindrical sound attenuation functions suggests that spherical model results more closely approximate observed sound attenuation.

  16. Characterizing large river sounds: Providing context for understanding the environmental effects of noise produced by hydrokinetic turbines

    SciTech Connect

    Bevelhimer, Mark S.; Deng, Z. Daniel; Scherelis, Constantin

    2016-01-01

    Underwater noise associated with the installation and operation of hydrokinetic turbines in rivers and tidal zones presents a potential environmental concern for fish and marine mammals. Comparing the spectral quality of sounds emitted by hydrokinetic turbines to natural and other anthropogenic sound sources is an initial step at understanding potential environmental impacts. Underwater recordings were obtained from passing vessels of different sizes and other underwater sound sources in both static and flowing waters. Static water measurements were taken in a lake with minimal background noise. Flowing water measurements were taken at a previously proposed deployment site for hydrokinetic turbines on the Mississippi River, where the sound of flowing water is included in background measurements. The size of vessels measured ranged from a small fishing boat with a 60 HP outboard motor to an 18-unit barge train being pushed upstream by tugboat. As expected, large vessels with large engines created the highest sound levels, and when compared to the sound created by an operating HK turbine were many times greater. A comparison of sound levels from the same sources at different distances using both spherical and cylindrical sound attenuation functions suggests that spherical model results more closely approximate observed values.

  17. Development of computer program ENAUDIBL for computation of the sensation levels of multiple, complex, intrusive sounds in the presence of residual environmental masking noise

    SciTech Connect

    Liebich, R. E.; Chang, Y.-S.; Chun, K. C.

    2000-03-31

    The relative audibility of multiple sounds occurs in separate, independent channels (frequency bands) termed critical bands or equivalent rectangular (filter-response) bandwidths (ERBs) of frequency. The true nature of human hearing is a function of a complex combination of subjective factors, both auditory and nonauditory. Assessment of the probability of individual annoyance, community-complaint reaction levels, speech intelligibility, and the most cost-effective mitigation actions requires sensation-level data; these data are one of the most important auditory factors. However, sensation levels cannot be calculated by using single-number, A-weighted sound level values. This paper describes specific steps to compute sensation levels. A unique, newly developed procedure is used, which simplifies and improves the accuracy of such computations by the use of maximum sensation levels that occur, for each intrusive-sound spectrum, within each ERB. The newly developed program ENAUDIBL makes use of ERB sensation-level values generated with some computational subroutines developed for the formerly documented program SPECTRAN.

  18. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, C. H.; Laux, C. O.

    1998-01-01

    This report describes progress during the second year of our research program on Infrared Signature Masking by Air Plasmas at Stanford University. This program is intended to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. Our previous annual report described spectral measurements and modeling of the radiation emitted between 3.2 and 5.5 microns by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3100 K. One of our goals was to examine the spectral emission of secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million Of CO2, which is the natural CO2 concentration in atmospheric air at room temperature, and a small amount of water vapor with an estimated mole fraction of 3.8 x 10(exp -4). As can be seen from Figure 1, it was found that the measured spectrum exhibited intense spectral features due to the fundamental rovibrational bands of NO at 4.9 - 5.5 microns and the V(3) band of CO2 (antisymmetric stretch) at 4.2-4.8 microns. These observations confirmed the well-known fact that infrared signatures between 4.15 - 5.5 microns can be masked by radiative emission in the interceptor's bow-shock. Figure I also suggested that the range 3.2 - 4.15 microns did not contain any significant emission features (lines or continuum) that could mask IR signatures. However, the signal-to-noise level, close to one in that range, precluded definite conclusions. Thus, in an effort to further investigate the spectral emission in the range of interest to signature masking problem, new measurements were made with a higher signal-to-noise ratio and an extended wavelength range.

  19. Overview of Mask Metrology

    NASA Astrophysics Data System (ADS)

    Rice, Bryan J.; Jindal, Vibhu; Lin, C. C.; Harris-Jones, Jenah; Kwon, Hyuk Joo; Ma, Hsing-Chien; Goldstein, Michael; Chan, Yau-Wai; Goodwin, Frank

    2011-11-01

    Extreme ultraviolet (EUV) lithography is the successor to optical lithography and will enable advanced patterning in semiconductor manufacturing processes down to the 8 nm half pitch technology node and beyond. However, before EUV can successfully be inserted into high volume manufacturing a few challenges must be overcome. Central among these remaining challenges is the requirement to produce "defect free" EUV masks. Mask blank defects have been one of the top challenges in the commercialization of extreme ultraviolet (EUV) lithography. To determine defect sources and devise mitigation solutions, detailed characterization of defects is critical. However, small defects pose challenges in metrology scale-up. SEMATECH has a comprehensive metrology strategy to address any defect larger than a 20 nm core size to obtain solutions for defect-free EUV mask blanks. SEMATECH's Mask Blank Development Center has been working since 2003 to develop the technology to support defect free EUV mask blanks. Since 2003, EUV mask blank defects have been reduced from 10000 of size greater than 100 nm to about a few tens at size 70 nm. Unfortunately, today's state of the art defect levels are still about 10 to 100 times higher than needed. Closing this gap requires progress in the various processes associated with glass substrate creation and multilayer deposition. That process development improvement in turn relies upon the availability of metrology equipment that can resolve and chemically characterize defects as small as 30 nm. The current defect reduction efforts at SEMATECH have intensively included a focus on inspection and characterization. The facility boasts nearly 100M of metrology hardware, including an FEI Titan TEM, Lasertec M1350 and M7360 tools, an actinic inspection tool, AFM, SPM, and scanning auger capabilities. The newly established Auger tool at SEMATECH can run a standard 6-inch mask blank and is already providing important information on sub-100 nm defects on EUV

  20. Effects of ship noise on the detectability of communication signals in the Lusitanian toadfish.

    PubMed

    Vasconcelos, Raquel O; Amorim, M Clara P; Ladich, Friedrich

    2007-06-01

    Underwater noise pollution is an increasing environmental problem which might affect communication, behaviour, fitness and consequently species' survival. The most common anthropogenic noises in aquatic habitats derive from shipping. In the present study we investigated the implications of noise pollution from a ship on the sound detectability, namely of conspecific vocalizations in the Lusitanian toadfish, Halobatrachus didactylus. Ambient and ferry-boat noises were recorded in the Tagus River estuary (Portugal), as well as toadfish sounds, and their sound pressure levels determined. Hearing sensitivities were measured under quiet lab conditions and in the presence of these masking noises at levels encountered in the field, using the auditory evoked potentials (AEP) recording technique. The Lusitanian toadfish is a hearing generalist, with best hearing sensitivity at low frequencies between 50 and 200 Hz (below 100 dB re. 1 microPa). Under ambient noise conditions, hearing was only slightly masked at lower frequencies. In the presence of ship noise, auditory thresholds increased considerably, by up to 36 dB, at most frequencies tested. This is mainly because the main energies of ferry-boat noise were within the most sensitive hearing range of this species. Comparisons between masked audiograms and sound spectra of the toadfish's mating and agonistic vocalizations revealed that ship noise decreased the ability to detect conspecific acoustic signals. This study provides the first evidence that fishes' auditory sensitivity can be impaired by ship noise and that acoustic communication, which is essential during agonistic encounters and mate attraction, might be restricted in coastal environments altered by human activity.

  1. MSB for ILT masks

    NASA Astrophysics Data System (ADS)

    Gramss, Juergen; Weidenmueller, Ulf; Stoeckel, Arnd; Jaritz, Renate; Doering, Hans-Joachim; Boettcher, Monika

    2011-03-01

    Multi Shaped Beam (MSB) throughput simulation results have already been published in the past. An IC mask set of a 32nm node logic device was one of the applications that had been analyzed in more detail. In this paper we want to highlight results of shot count and write time evaluations done for Inverse Lithography Technology (ILT) masks targeting the 22nm technology node. The test pattern data we used for these practice-oriented analyses was designed by DNP / Japan and created by Luminescent Technologies, Inc. / USA. To achieve reliable evaluation results, the influence of different MSB configurations on shot count and mask write time has been taken into account and will be discussed here. Exposure results of pattern details are presented and compared with the fracturing result. The MSB engineering tool we used for our investigations covers such major components like an electron-optical column, a precision x/y stage and the MSB data path.

  2. EFFECT OF MASKED REGIONS ON WEAK-LENSING STATISTICS

    SciTech Connect

    Shirasaki, Masato; Yoshida, Naoki; Hamana, Takashi

    2013-09-10

    Sky masking is unavoidable in wide-field weak-lensing observations. We study how masks affect the measurement of statistics of matter distribution probed by weak gravitational lensing. We first use 1000 cosmological ray-tracing simulations to examine in detail the impact of masked regions on the weak-lensing Minkowski Functionals (MFs). We consider actual sky masks used for a Subaru Suprime-Cam imaging survey. The masks increase the variance of the convergence field and the expected values of the MFs are biased. The bias then compromises the non-Gaussian signals induced by the gravitational growth of structure. We then explore how masks affect cosmological parameter estimation. We calculate the cumulative signal-to-noise ratio (S/N) for masked maps to study the information content of lensing MFs. We show that the degradation of S/N for masked maps is mainly determined by the effective survey area. We also perform simple {chi}{sup 2} analysis to show the impact of lensing MF bias due to masked regions. Finally, we compare ray-tracing simulations with data from a Subaru 2 deg{sup 2} survey in order to address if the observed lensing MFs are consistent with those of the standard cosmology. The resulting {chi}{sup 2}/n{sub dof} = 29.6/30 for three combined MFs, obtained with the mask effects taken into account, suggests that the observational data are indeed consistent with the standard {Lambda}CDM model. We conclude that the lensing MFs are a powerful probe of cosmology only if mask effects are correctly taken into account.

  3. Effect of broadband-noise masking on the behavioral response of a harbor porpoise (Phocoena phocoena) to 1-s duration 6-7 kHz sonar up-sweeps.

    PubMed

    Kastelein, Ronald A; Steen, Nele; de Jong, Christ; Wensveen, Paul J; Verboom, Willem C

    2011-04-01

    Naval sonar systems produce signals which may affect the behavior of harbor porpoises, though their effect may be reduced by ambient noise. To show how natural ambient noise influences the effect of sonar sweeps on porpoises, a porpoise in a pool was exposed to 1-s duration up-sweeps, similar in frequency range (6-7 kHz) to those of existing naval sonar systems. The sweep signals had randomly generated sweep intervals of 3-7 s (duty cycle: 19%). Behavioral parameters during exposure to signals were compared to those during baseline periods. The sessions were conducted under five background noise conditions: the local normal ambient noise and four conditions mimicking the spectra for wind-generated noise at Sea States 2-8. In all conditions, the sweeps caused the porpoise to swim further away from the transducer, surface more often, swim faster, and breathe more forcefully than during the baseline periods. However, the higher the background noise level, the smaller the effects of the sweeps on the surfacing behavior of the porpoise. Therefore, the effects of naval sonar systems on harbor porpoises are determined not only by the received level of the signals and the hearing sensitivity of the animals but also by the background noise.

  4. Combining energetic and informational masking for speech identification

    NASA Astrophysics Data System (ADS)

    Kidd, Gerald; Mason, Christine R.; Gallun, Frederick J.

    2005-08-01

    This study examined combinations of energetic and informational maskers in speech identification. Speech targets and maskers (speech or noise) were processed and filtered into sets of 15 narrow frequency bands. The target was the sum of eight randomly selected bands. More masking occurred for speech maskers than for spectrally matched noise maskers regardless of whether the masker bands overlapped the target bands. The greater effect of the speech maskers was interpreted as due to informational masking. When the masker was comprised of nonoverlapping bands of speech, the addition of bands of noise overlapping the speech masker, but not the speech target, reduced the overall amount of masking. Surprisingly, presenting the noise to the ear contralateral to the target and masker produced an even greater release from masking. The contralateral noise was apparently sufficient to cause a slight change in the image of the ipsilateral speech masker, possibly pulling it away from the target enough to allow the focus of attention on the target. This finding is consistent with the interpretation that in some conditions small binaural differences may be sufficient to cause, or significantly strengthen, the perceptual segregation of sounds.

  5. Masked mycotoxins: A review

    PubMed Central

    Berthiller, Franz; Crews, Colin; Dall'Asta, Chiara; Saeger, Sarah De; Haesaert, Geert; Karlovsky, Petr; Oswald, Isabelle P; Seefelder, Walburga; Speijers, Gerrit; Stroka, Joerg

    2013-01-01

    The aim of this review is to give a comprehensive overview of the current knowledge on plant metabolites of mycotoxins, also called masked mycotoxins. Mycotoxins are secondary fungal metabolites, toxic to human and animals. Toxigenic fungi often grow on edible plants, thus contaminating food and feed. Plants, as living organisms, can alter the chemical structure of mycotoxins as part of their defence against xenobiotics. The extractable conjugated or non-extractable bound mycotoxins formed remain present in the plant tissue but are currently neither routinely screened for in food nor regulated by legislation, thus they may be considered masked. Fusarium mycotoxins (deoxynivalenol, zearalenone, fumonisins, nivalenol, fusarenon-X, T-2 toxin, HT-2 toxin, fusaric acid) are prone to metabolisation or binding by plants, but transformation of other mycotoxins by plants (ochratoxin A, patulin, destruxins) has also been described. Toxicological data are scarce, but several studies highlight the potential threat to consumer safety from these substances. In particular, the possible hydrolysis of masked mycotoxins back to their toxic parents during mammalian digestion raises concerns. Dedicated chapters of this article address plant metabolism as well as the occurrence of masked mycotoxins in food, analytical aspects for their determination, toxicology and their impact on stakeholders. PMID:23047235

  6. COAs: Behind the Masks.

    ERIC Educational Resources Information Center

    Birke, Szifra

    1993-01-01

    Provides information on alcoholism and codependency to help teachers identify and respond to children of alcoholics (COAs). Discusses characteristics of alcoholic homes and problems encountered by children and adult COAs. Examines survival "masks" of COAs, including hero, rebel, adjustor, clown, and caretaker. Lists organizational,…

  7. Apodized Phase Mask Coronagraphs

    NASA Astrophysics Data System (ADS)

    Carlotti, Alexis

    2013-01-01

    Among the optical instruments proposed to detect and characterize exoplanets, phase masks coronagraphs offer very small inner working angles. Designed for off-axis telescopes, their performance is greatly reduced when used with centrally obstructed apertures such as those of the Palomar telescope, the very large telescope, or the James Webb space telescope. However, a clear circular aperture is not the only pupil shape for which a phase mask coronagraph can work properly. In fact, for a given centrally obstructed aperture, we show that it is possible to compute optimal apodizers that help achieve stellar extinction levels similar to those obtained in the ideal case of an off-axis telescope. Trade-offs exist between these levels, the transmission of the apodizer, and the area covered by the Lyot stop. We detail the Fourier optics formalism that makes these optimizations possible, as well as a few examples of shaped pupils. Some are designed for a four-quadrants phase mask, and some others for a vortex phase mask. We also offer a comparison with a coronagraph solely composed of a shaped pupil.

  8. Masked mycotoxins: a review.

    PubMed

    Berthiller, Franz; Crews, Colin; Dall'Asta, Chiara; Saeger, Sarah De; Haesaert, Geert; Karlovsky, Petr; Oswald, Isabelle P; Seefelder, Walburga; Speijers, Gerrit; Stroka, Joerg

    2013-01-01

    The aim of this review is to give a comprehensive overview of the current knowledge on plant metabolites of mycotoxins, also called masked mycotoxins. Mycotoxins are secondary fungal metabolites, toxic to human and animals. Toxigenic fungi often grow on edible plants, thus contaminating food and feed. Plants, as living organisms, can alter the chemical structure of mycotoxins as part of their defence against xenobiotics. The extractable conjugated or non-extractable bound mycotoxins formed remain present in the plant tissue but are currently neither routinely screened for in food nor regulated by legislation, thus they may be considered masked. Fusarium mycotoxins (deoxynivalenol, zearalenone, fumonisins, nivalenol, fusarenon-X, T-2 toxin, HT-2 toxin, fusaric acid) are prone to metabolisation or binding by plants, but transformation of other mycotoxins by plants (ochratoxin A, patulin, destruxins) has also been described. Toxicological data are scarce, but several studies highlight the potential threat to consumer safety from these substances. In particular, the possible hydrolysis of masked mycotoxins back to their toxic parents during mammalian digestion raises concerns. Dedicated chapters of this article address plant metabolism as well as the occurrence of masked mycotoxins in food, analytical aspects for their determination, toxicology and their impact on stakeholders.

  9. Competing for Consciousness: Prolonged Mask Exposure Reduces Object Substitution Masking

    ERIC Educational Resources Information Center

    Goodhew, Stephanie C.; Visser, Troy A. W.; Lipp, Ottmar V.; Dux, Paul E.

    2011-01-01

    In object substitution masking (OSM) a sparse, temporally trailing 4-dot mask impairs target identification, even though it has different contours from, and does not spatially overlap with the target. Here, we demonstrate a previously unknown characteristic of OSM: Observers show reduced masking at prolonged (e.g., 640 ms) relative to intermediate…

  10. Analysis of environmental contaminates in hair using an ion trap mass spectrometer with a filtered noise field waveboard

    SciTech Connect

    Alcaraz, A.; Hulsey, S.S.; Frantz, C.E.; Andresen, B.D.

    1994-12-31

    A variety of methods have been established using mass spectrometry (MS) for the analysis of chemicals in hair. Much of this past work has been focused on the detection of drugs of abuse. Human hair has been analyzed either directly by probe distillation (DIP) with some preliminary clean-up using HPLC or solid phase extraction (SPE). However, established drug analysis methods do not apply for the detection of some environmental contaminates. In this study, the authors selected 2,4,6-trinitrotoluene (TNT) and malathion as the target compounds. In addition two types of hair samples were analyzed: (1) human hair fortified with either TNT or malathion and (2) hair from mice who ingested the same analytes. The analytical method was DIP-EI-MS/MS with an ion trap mass spectrometer equipped with a filtered noise field wave board.

  11. To enhance imaging performance of hybrid imaging systems by using two asymmetrical phase masks.

    PubMed

    Le, Van Nhu; Chen, Shouqian; Fan, Zhigang; Pham, Nghia Minh

    2016-02-10

    We propose the use of two asymmetrical phase masks combined with the subtracted imaging method to enhance the signal-to-noise ratio in wavefront coding systems. This subtracted imaging technique is similar to the variable pinhole diameter in confocal microscopy. Two different phase modulations of same phase masks are employed to promote the magnitude of the optical transfer function (OTF). The ratio factor is used to control the phase variation between two phase masks. The noise of decoded images is suppressed owing to the higher magnitude of the OTF than the wavefront coding systems with a phase mask. A tangent phase mask as an example is used to demonstrate our concept. Simulated results show that the performance promotion controls noise amplification of decoded images while maintaining a depth-of-field extension.

  12. Critical ratios of beluga whales (Delphinapterus leucas) and masked signal duration.

    PubMed

    Erbe, Christine

    2008-10-01

    This article examines the masking of a complex beluga vocalization by natural and anthropogenic noise. The call consisted of six 150 ms pulses exhibiting spectral peaks between 800 Hz and 8 kHz. Comparing the spectra and spectrograms of the call and noises at detection threshold showed that the animal did not hear the entire call at threshold. It only heard parts of the call in frequency and time. From the masked hearing thresholds in broadband continuous noises, critical ratios were computed. Fletcher critical bands were narrower than either 15 or 111 of an octave at the low frequencies of the call (<2 kHz), depending on which frequency the animal cued on. From the masked hearing thresholds in intermittent noises, the audible signal duration at detection threshold was computed. The intermittent noises differed in gap length, gap number, and masking, but the total audible signal duration at threshold was the same: 660 ms. This observation supports a multiple-looks model. The two amplitude modulated noises exhibited weaker masking than the unmodulated noises hinting at a comodulation masking release.

  13. Evaluation of mask manufacturing efficiency using mask data rank information

    NASA Astrophysics Data System (ADS)

    Kato, Kokoro; Endo, Masakazu; Inoue, Tadao; Yamabe, Masaki; Nakatake, Shigetoshi

    2010-05-01

    The photomask cost is becoming one of the challenging issues in the semiconductor industry, as the cost of photomasks has been rising year by year. ASET started Mask D2I (Mask Design, Drawing and Inspection Technology) project with the sponsorship from the NEDO (New Energy and Industrial Technology Development Organization) in 2006 for the purpose of the mask cost reduction. In earlier papers[1-5], we introduced the idea of photomask data prioritization method which is referred to as Mask Data Rank (MDR). We have built our software system to convert Design Intent (DI) to MDR with cooperation of STARC. Then we showed the results of experiments with mask data provided by semiconductor companies. In this paper we show the additional report of mask inspection experiments using real photomasks. Then we show the evaluation results about mask drawing time reduction using MDR flow. Finally we introduce detailed algorithm to extract design intent from analog circuits.

  14. Masking Release in Children and Adults with Hearing Loss When Using Amplification

    ERIC Educational Resources Information Center

    Brennan, Marc; McCreery, Ryan; Kopun, Judy; Lewis, Dawna; Alexander, Joshua; Stelmachowicz, Patricia

    2016-01-01

    Purpose: This study compared masking release for adults and children with normal hearing and hearing loss. For the participants with hearing loss, masking release using simulated hearing aid amplification with 2 different compression speeds (slow, fast) was compared. Method: Sentence recognition in unmodulated noise was compared with recognition…

  15. Characterizing large river sounds: Providing context for understanding the environmental effects of noise produced by hydrokinetic turbines

    DOE PAGES

    Bevelhimer, Mark S.; Deng, Z. Daniel; Scherelis, Constantin C.

    2016-01-06

    Underwaternoise associated with the installation and operation of hydrokinetic turbines in rivers and tidal zones presents a potential environmental concern for fish and marine mammals. Comparing the spectral quality of sounds emitted by hydrokinetic turbines to natural and other anthropogenic sound sources is an initial step at understanding potential environmental impacts. Underwater recordings were obtained from passing vessels and natural underwater sound sources in static and flowing waters. Static water measurements were taken in a lake with minimal background noise. Flowing water measurements were taken at a previously proposed deployment site for hydrokinetic turbines on the Mississippi River, where soundsmore » created by flowing water are part of all measurements, both natural ambient and anthropogenic sources. Vessel sizes ranged from a small fishing boat with 60 hp outboard motor to an 18-unit barge train being pushed upstream by tugboat. As expected, large vessels with large engines created the highest sound levels, which were, on average, 40 dB greater than the sound created by an operating hydrokinetic turbine. As a result, a comparison of sound levels from the same sources at different distances using both spherical and cylindrical sound attenuation functions suggests that spherical model results more closely approximate observed sound attenuation.« less

  16. Characterizing large river sounds: Providing context for understanding the environmental effects of noise produced by hydrokinetic turbines

    SciTech Connect

    Bevelhimer, Mark S.; Deng, Z. Daniel; Scherelis, Constantin C.

    2016-01-06

    Underwaternoise associated with the installation and operation of hydrokinetic turbines in rivers and tidal zones presents a potential environmental concern for fish and marine mammals. Comparing the spectral quality of sounds emitted by hydrokinetic turbines to natural and other anthropogenic sound sources is an initial step at understanding potential environmental impacts. Underwater recordings were obtained from passing vessels and natural underwater sound sources in static and flowing waters. Static water measurements were taken in a lake with minimal background noise. Flowing water measurements were taken at a previously proposed deployment site for hydrokinetic turbines on the Mississippi River, where sounds created by flowing water are part of all measurements, both natural ambient and anthropogenic sources. Vessel sizes ranged from a small fishing boat with 60 hp outboard motor to an 18-unit barge train being pushed upstream by tugboat. As expected, large vessels with large engines created the highest sound levels, which were, on average, 40 dB greater than the sound created by an operating hydrokinetic turbine. As a result, a comparison of sound levels from the same sources at different distances using both spherical and cylindrical sound attenuation functions suggests that spherical model results more closely approximate observed sound attenuation.

  17. RHIC Prefire Protection Masks

    SciTech Connect

    Drees, A.; Biscardi, C.; Curcio, T.; Gassner, D.; DeMonte, V.; DeSanto, L.; Fu, W.; Liaw, C. J.; Montag, C.; Thieberger, P.; Yip, K.

    2015-01-07

    The protection of the RHIC experimental detectors from damage due to beam hitting close upstream elements in cases of abort kicker prefires requires some dedicated precautionary measures with two general options: to bring the beam close to a limiting aperture (i.e. the beam pipe wall), as far upstream of the detector components as possible or, alternatively, to bring a limiting aperture close to the circulating beam. During the FY 2014 RHIC Heavy Ion run the first option was chosen because of the limited time available for preparation before the start of the run. For future runs the second option, in this case the installation of dual-sided movable masks, is preferred. The installation of the masks, one per ring, is planned before the start of the FY 2015 run.

  18. On Masking Effect

    DTIC Science & Technology

    1993-07-01

    solution will perform better than the others and present experimental data supportive of the analysis. This investigation is based on simulated robot...solution will perform better than the agent’s task is to catch the evasion agent. Both agents others, and present experimental data supportive of the...Masking interception, and the resultant time lost from hiding and The previous section ruled out refinement stratgies replanning. Without the learned rule

  19. Masked multichannel analyzer

    DOEpatents

    Winiecki, Alan L.; Kroop, David C.; McGee, Marilyn K.; Lenkszus, Frank R.

    1986-01-01

    An analytical instrument and particularly a time-of-flight-mass spectrometer for processing a large number of analog signals irregularly spaced over a spectrum, with programmable masking of portions of the spectrum where signals are unlikely in order to reduce memory requirements and/or with a signal capturing assembly having a plurality of signal capturing devices fewer in number than the analog signals for use in repeated cycles within the data processing time period.

  20. Masked multichannel analyzer

    DOEpatents

    Winiecki, A.L.; Kroop, D.C.; McGee, M.K.; Lenkszus, F.R.

    1984-01-01

    An analytical instrument and particularly a time-of-flight-mass spectrometer for processing a large number of analog signals irregularly spaced over a spectrum, with programmable masking of portions of the spectrum where signals are unlikely in order to reduce memory requirements and/or with a signal capturing assembly having a plurality of signal capturing devices fewer in number than the analog signals for use in repeated cycles within the data processing time period.

  1. Masks: Culture and Kids.

    ERIC Educational Resources Information Center

    Patterson, MaryEllen; And Others

    This guide describes a 7-day lesson plan to be used with bilingual 3rd and 4th graders and 6th, 7th, and 8th graders in English-as-a-Second-Language (ESL) classes. The guide shows how mask making can be tied into each class, and then how to pull the classes together for the older students to become peer tutors to the younger ones in the…

  2. The Attentional Dynamics of Masked Detection

    ERIC Educational Resources Information Center

    Smith, Philip L.; Wolfgang, Bradley J.

    2004-01-01

    A dichoptic masking procedure was used to test whether the mask-dependent cuing effects found in luminance detection by P. L. Smith (2000a) were due to integration masking or interruption masking. Attentional cuing enhanced detection sensitivity (d') when stimuli were backwardly masked with either dichoptic or monoptic masks, whereas no cuing…

  3. Mask strategy at International SEMATECH

    NASA Astrophysics Data System (ADS)

    Kimmel, Kurt R.

    2002-08-01

    International SEMATECH (ISMT) is a consortium consisting of 13 leading semiconductor manufacturers from around the globe. Its objective is to develop the infrastructure necessary for its member companies to realize the International Technology Roadmap for Semiconductors (ITRS) through efficiencies of shared development resources and knowledge. The largest area of effort is lithography, recognized as a crucial enabler for microelectronics technology progress. Within the Lithography Division, most of the efforts center on mask-related issues. The development strategy at International SEMATCH will be presented and the interlock of lithography projects clarified. Because of the limited size of the mask production equipment market, the business case is weak for aggressive investment commensurate with the pace of the International Technology Roadmap for Semiconductors. With masks becoming the overwhelming component of lithography cost, new ways of reducing or eliminating mask costs are being explored. Will mask technology survive without a strong business case? Will the mask industry limit the growth of the semiconductor industry? Are advanced masks worth their escalating cost? An analysis of mask cost from the perspective of mask value imparted to the user is presented with examples and generic formulas for the reader to apply independently. A key part to the success for both International SEMATECH and the industry globally will be partnerships on both the local level between mask-maker and mask-user, and the macro level where global collaborations will be necessary to resolve technology development cost challenges.

  4. EUV mask black border evolution

    NASA Astrophysics Data System (ADS)

    Turley, Christina; Bonam, Ravi; Gallagher, Emily; Grohs, Jonathan; Kagawa, Masayuki; Kindt, Louis; Narita, Eisuke; Nash, Steven; Sakamoto, Yoshifumi

    2014-10-01

    The black border is a frame created by removing all the multilayers on the EUV mask in the region around the chip. It is created to prevent exposure of adjacent fields when printing an EUV mask on a wafer. Papers have documented its effectiveness. As the technology transitions into manufacturing, the black border must be optimized from the initial mask making process through its life. In this work, the black border is evaluated in three stages: the black border during fabrication, the final sidewall profile, and extended lifetime studies. This work evaluates the black border through simulations and physical experiments. The simulations address concerns for defects and sidewall profiles. The physical experiments test the current black border process. Three masks are used: one mask to test how black border affects the image placement of features on mask and two masks to test how the multilayers change through extended cleans. Data incorporated in this study includes: registration, reflectivity, multilayer structure images and simulated wafer effects. By evaluating the black border from both a mask making perspective and a lifetime perspective, we are able to characterize how the structure evolves. The mask data and simulations together predict the performance of the black border and its ability to maintain critical dimensions on wafer. In this paper we explore what mask changes occur and how they will affect mask use.

  5. Bioacoustics of Monterey Bay Pinnipeds: Auditory Fatigue and Masking.

    DTIC Science & Technology

    2007-11-02

    lions ( Zalophus californianus ) under unmasked conditions, masked conditions, and following exposure to noise. Thresholds were determined using a 50...frequency in air and under water; 3) Zalophus is more sensitive to aerial sounds than underwater sounds; 4) Zalophus is susceptible to age related

  6. Masks in imaging flow cytometry.

    PubMed

    Dominical, Venina; Samsel, Leigh; McCoy, J Philip

    2017-01-01

    Data analysis in imaging flow cytometry incorporates elements of flow cytometry together with other aspects of morphological analysis of images. A crucial early step in this analysis is the creation of a mask to distinguish the portion of the image upon which further examination of specified features can be performed. Default masks are provided by the manufacturer of the imaging flow cytometer but additional custom masks can be created by the individual user for specific applications. Flawed or inaccurate masks can have a substantial negative impact on the overall analysis of a sample, thus great care must be taken to ensure the accuracy of masks. Here we discuss various types of masks and cite examples of their use. Furthermore we provide our insight for how to approach selecting and assessing the optimal mask for a specific analysis.

  7. Mask requirements for advanced lithography

    NASA Astrophysics Data System (ADS)

    Trybula, Walter J.; Engelstad, Roxann L.

    1998-06-01

    Within the n ext 10 years, sub-100 nm features will be required for state-of-the-industry devices. The tolerances for errors at 100 nm or less are substantially smaller than can be achieved today. A critical element of the error budget is the mask. For the 100 nm generation, the 4x mask image placement requirement is 20 nm with CD requirements as low as 9 nm. The challenge would be significant if the only improvement were to develop superior optical masks. There are multiple advanced technologies that are vying to be the successor to optical lithography. Each of these has a unique mask requirement. The leading contenders for the next generation are 1x x-ray, projection e-beam, ion beam, EUV and cell projection e-beam. The x-ray design is a proximity system that employs a 1x membrane mask. Projection e-beam uses a membrane mask with stabilizing struts. Ion beam lithography employs a stencil membrane mask with a carbon coating. EUV employs a 13 nm radiation source that requires a reflective mask. Cell projection e-beam has 25x or greater image masks that are stitched on the wafer. All the technologies indicated above. Once a total error budget for the mask is known, it is necessary to divide the total into the constituent parts. The major sources of distortion can be categorized into eight areas: mask blank processing, e- beam writing, pattern transfer, pellicle effects, mounting, thermal loadings, dynamic effects during exposure and radiation damage. The distortions introduced by each of these depend upon the type of mask; so, individual mask calculations must be made. The purpose of this paper is to review the modeling requirements of each of the categories and to highlight some results from each of the mask configurations.

  8. Temporal Masking Contributions of Inherent Envelope Fluctuations for Listeners with Normal and Impaired Hearing

    NASA Astrophysics Data System (ADS)

    Svec, Adam

    Gaussian noise (GN) simultaneous maskers yield higher masked thresholds for pure tones than low-fluctuation noise (LFN) simultaneous maskers for listeners with normal hearing. This increased residual masking is thought to be due to inherent fluctuations in the temporal envelope of Gaussian noise, but these masking effects using forward maskers have been previously unexamined. Because differences in forward masking due to age and hearing loss are known, the first study measured forward-masked detection thresholds for younger and older adults with normal hearing (NH) and older adults with hearing loss (HI) for a 4000 Hz pure-tone probe at a single masker-probe delay in narrowband noises with maximal (GN) or minimal (LFN) inherent envelope fluctuations. As predicted, results suggested that no effect of age was observed. Surprisingly, forward-masked threshold differences between GN and LFN, an estimate of the magnitude of the effect of inherent masker envelope fluctuations, were not significantly different for older HI listeners compared to younger or older NH listeners. Due to the surprising similarities between listeners with normal and impaired hearing, the second study was designed to assess effects of hearing loss on the slopes and magnitudes of recovery from forward maskers that varied in inherent envelope fluctuations for masker-probe delays of 25, 50, and 75 ms. In addition to measuring these effects centered at 4000 Hz, forward-masked thresholds were also measured at 2000 Hz, a region of better hearing for the HI listeners. As hypothesized, regardless of masker fluctuations, slopes of recovery from forward masking were shallower for HI than NH listeners in all conditions. At 4000 Hz, additional residual masking was greater in HI than NH listeners at the longest masker-probe delays; whereas, no differences in additional residual masking between HI and NH listeners were observed for 2000 Hz. These results suggest that the masking effects from inherent envelope

  9. Perceptually-weighted evaluation criteria for segmentation masks in video sequences.

    PubMed

    Villegas, Paulo; Marichal, Xavier

    2004-08-01

    In order to complement subjective evaluation of the quality of segmentation masks, this paper introduces a procedure for automatically assessing this quality. Algorithmically computed figures of merit are proposed. Assuming the existence of a perfect reference mask (ground truth), generated manually or with a reliable procedure over a test set, these figures of merit take into account visually desirable properties of a segmentation mask in order to provide the user with metrics that best quantify the spatial and temporal accuracy of the segmentation masks. For the sake of easy interpretation, results are presented on a peaked signal-to-noise ratio-like logarithmic scale.

  10. Acoustic and economic analysis of the use of palm tree pruning waste in noise barriers to mitigate the environmental impact of motorways.

    PubMed

    Gil-Lopez, Tomas; Medina-Molina, Manuel; Verdu-Vazquez, Amparo; Martel-Rodriguez, Basilio

    2017-04-15

    This research has a twofold environmental benefit. On the one hand, there is the recycling of a waste by-product and, on the other hand, the reduction of traffic noise pollution levels. The objective of this study is to determine and evaluate the use of a mixture of shredded palm tree pruning waste with dampened topsoil in the construction of noise barriers. With a view to efficiently recycling pruning waste and using an environmentally-friendly material which does not pose any environmental risks at the end of its useful life, the composition offering the best sound absorption has been analyzed. Based on the results obtained, a completely eco-friendly roadside noise barrier (RNB) 1:1 scale model was built, and noise levels measured at various points close to it. Significant sound absorption benefits were detected, not only in the shaded area behind the barrier, but also in the unprotected area immediately above the barrier. Furthermore, the economic feasibility of both the construction and recycling processes has been calculated.

  11. Mask alignment system for semiconductor processing

    DOEpatents

    Webb, Aaron P.; Carlson, Charles T.; Weaver, William T.; Grant, Christopher N.

    2017-02-14

    A mask alignment system for providing precise and repeatable alignment between ion implantation masks and workpieces. The system includes a mask frame having a plurality of ion implantation masks loosely connected thereto. The mask frame is provided with a plurality of frame alignment cavities, and each mask is provided with a plurality of mask alignment cavities. The system further includes a platen for holding workpieces. The platen may be provided with a plurality of mask alignment pins and frame alignment pins configured to engage the mask alignment cavities and frame alignment cavities, respectively. The mask frame can be lowered onto the platen, with the frame alignment cavities moving into registration with the frame alignment pins to provide rough alignment between the masks and workpieces. The mask alignment cavities are then moved into registration with the mask alignment pins, thereby shifting each individual mask into precise alignment with a respective workpiece.

  12. Mask fabrication process

    DOEpatents

    Cardinale, Gregory F.

    2000-01-01

    A method for fabricating masks and reticles useful for projection lithography systems. An absorber layer is conventionally patterned using a pattern and etch process. Following the step of patterning, the entire surface of the remaining top patterning photoresist layer as well as that portion of an underlying protective photoresist layer where absorber material has been etched away is exposed to UV radiation. The UV-exposed regions of the protective photoresist layer and the top patterning photoresist layer are then removed by solution development, thereby eliminating the need for an oxygen plasma etch and strip and chances for damaging the surface of the substrate or coatings.

  13. Masks of the Universe

    NASA Astrophysics Data System (ADS)

    Harrison, Edward

    2003-05-01

    Preface; Introducing the masks; Part I. Worlds in the Making: 1. The magic Universe; 2. The mythic Universe; 3. The geometric Universe; 4. The medieval Universe; 5. The infinite Universe; 6. The mechanistic Universe; Part II. The Heart Divine: 7. Dance of the atoms and waves; 8. Fabric of space and time; 9. Nearer to the heart's desire; 10. The cosmic tide; 11. Do dreams ever come true?; Part III. The Cloud of Unknowing: 12. The witch universe; 13. The spear of Archytas; 14. All that is made; 15. The cloud of unknowing; 16. Learned ignorance.

  14. Disrupting the Transmission of Influenza A: Face Masks and Ultraviolet Light as Control Measures

    PubMed Central

    Weiss, Martin Meyer; Weiss, Peter D.; Weiss, Danielle E.; Weiss, Joseph B.

    2007-01-01

    In the event of an influenza pandemic, where effective vaccine and antiviral drugs may be lacking, disrupting environmental transmission of the influenza virus will be the only viable strategy to protect the public. We discuss 2 such modalities, respirators (face masks) and ultraviolet (UV) light. Largely overlooked, the potential utility of each is underappreciated. The effectiveness of disposable face masks may be increased by sealing the edges of the mask to the face. Reusable masks should be stockpiled, because the supply of disposable masks will likely prove inadequate. UV light, directed overhead, may be beneficial in hospitals and nursing homes. PMID:17413061

  15. Getting the cocktail party started: masking effects in speech perception

    PubMed Central

    Evans, S; McGettigan, C; Agnew, ZK; Rosen, S; Scott, SK

    2016-01-01

    Spoken conversations typically take place in noisy environments and different kinds of masking sounds place differing demands on cognitive resources. Previous studies, examining the modulation of neural activity associated with the properties of competing sounds, have shown that additional speech streams engage the superior temporal gyrus. However, the absence of a condition in which target speech was heard without additional masking made it difficult to identify brain networks specific to masking and to ascertain the extent to which competing speech was processed equivalently to target speech. In this study, we scanned young healthy adults with continuous functional Magnetic Resonance Imaging (fMRI), whilst they listened to stories masked by sounds that differed in their similarity to speech. We show that auditory attention and control networks are activated during attentive listening to masked speech in the absence of an overt behavioural task. We demonstrate that competing speech is processed predominantly in the left hemisphere within the same pathway as target speech but is not treated equivalently within that stream, and that individuals who perform better in speech in noise tasks activate the left mid-posterior superior temporal gyrus more. Finally, we identify neural responses associated with the onset of sounds in the auditory environment, activity was found within right lateralised frontal regions consistent with a phasic alerting response. Taken together, these results provide a comprehensive account of the neural processes involved in listening in noise. PMID:26696297

  16. Resampling masks for phase-shifting digital holography

    NASA Astrophysics Data System (ADS)

    Zhang, Wenhui; Cao, Liangcai; Zhang, Hao; Zong, Song; Jin, Guofan

    2016-10-01

    Holographic imaging is degraded severely by the speckle or incoherent noise. In this work, resampling mask method based on phase-shifting digital holography is proposed to reduce the reconstruction noise. The zero-order and the conjugate term of the hologram can be eliminated with four-step phase-shifting digital holography (PSDH). The complex amplitude of the object after propagation can be calculated by the phase-shifting algorithm. A phase-only spatial light modulator is used to realize PSDH in the experiment. The complex amplitude is encoded into several parts by resampling masks. A high quality reconstruction image with low noise is achieved through the superposition of the individually reconstruction of coded complex amplitudes. The experiment data go well with the asymptotic function. This method can be used for digital holographic imaging of the biological samples and microstructures. Experimental results prove the feasibility of this proposed method.

  17. Trends in mask data preparation

    NASA Astrophysics Data System (ADS)

    Fujimura, Aki; Pang, Liyong; Su, Bo; Choi, Yohan

    2014-10-01

    Whether for VSB mask writing or for multibeam mask writing, the shapes we need to write on masks are increasingly complex, increasingly curvilinear, and smaller in minimum width and space. The overwhelming trend in mask data preparation (MDP) is the shift from deterministic, rule-based, geometric, context-independent, shape-modulated, rectangular processing to statistical, simulation-based, context-dependent, dose- and shape-modulated any-shape processing. The paper briefly surveys the history of MDP, and explains through a simulation-based study that 50nm line and space is the tipping point where rule-based processing gives away to simulation-based processing.

  18. A Masked Photocathode in Photoinjector

    SciTech Connect

    Qiang, Ji

    2010-12-14

    In this paper, we propose a masked photocathode inside the photoinjector for generating high brightness election beam. Instead of mounting the photocathode onto an electrode, an electrode with small hole is used as a mask to shield the photocathode from the accelerating vacuum chamber. Using such a masked photocathode will make the replacement of photocathode material easy by rotating the photocathode behind the electrode into the hole. Furthermore, this helps reduce the dark current or secondary electron emission from the photocathode material. The masked photocathode also provides transverse cut-off to a Gaussian laser beam that reduces electron beam emittance growth from nonlinear space-charge effects.

  19. Masked hypertension: a systematic review.

    PubMed

    Bobrie, Guillaume; Clerson, Pierre; Ménard, Joël; Postel-Vinay, Nicolas; Chatellier, Gilles; Plouin, Pierre-François

    2008-09-01

    The purpose of this research was to review the literature on masked hypertension. Studies, reviews and editorials on masked hypertension were identified by PubMed, Pascal BioMed and Cochrane literature systematic searches. Then, we carried out a meta-analysis of the six cohort studies reporting quantitative data for masked hypertension prognosis. There is still no clear consensus definition of masked hypertension and the reproducibility of the phenomenon is unknown. Nevertheless, the prevalence of masked hypertension seems to lie between 8 and 20%, and can be up to 50% in treated hypertensive patients. Subjects with masked hypertension have a higher risk of cardiovascular accidents [hazard ratios: 1.92 (1.51-2.44)] than normotensive subjects. This is due to a possible failure to recognize and appropriately manage this particular form of hypertension, the frequent association with other risk factors and coexisting target organ damage. The remaining unresolved questions are as follows: is masked hypertension a clinical entity that requires identification and characterization or a statistical phenomenon linked to the variability of blood pressure measurements?; because screening of the entire population is not feasible, how to identify individuals with masked hypertension?; and, in the absence of randomized trial, how to treat masked hypertension?

  20. Akathisia masked by hypokinesia.

    PubMed

    Tuisku, K; Lauerma, H; Holi, M M; Honkonen, T; Rimon, R

    2000-07-01

    Here, we will discuss the concept of subjective akathisia and present a patient case. Our patient was suffering from neuroleptic-induced hypokinesia and akathisia at the same time. The typical motor manifestations of akathisia were masked by hypokinesia, which made the diagnosis difficult. However, the subjective symptoms of akathisia were evident and distressing. Although not observable to bare eye, the pathognomonic pattern of motor activity detected in akathisia was demonstrated by actometric recording. Changing the conventional neuroleptic to an atypical one brought relief to the subjective symptoms of akathisia and hypokinesia, while the motor activity was clearly diminished in actometric recording. Actometric recording may be useful in diagnosing akathisia masked by hypokinesia, but the typical subjective symptoms of akathisia should not be ignored, even when actometry is not available to demonstrate the missing motor component of akathisia. Not only akathisia defined by DSM-IV but also subjective akathisia should be adequately treated to relieve the subjective distress, and to diminish the unfavorable effects on psychotic symptoms, behavior, and drug compliance.

  1. Preliminary observations of infants' detection of backward masked tones

    NASA Astrophysics Data System (ADS)

    Werner, Lynne A.; Parrish, Heather K.

    2002-05-01

    Backward masked thresholds appear to have a prolonged developmental course compared to other measures of auditory capacity, but backward masking has not been studied in infant listeners. The present study examined 7-9-month-old infants' detection of 20-ms, 1-kHz pure tones masked by a 50-ms, 2.5-kHz-lowpass noise. The interval between the offset of the tone and the onset of the masker was 0 ms. Both stimuli had 5-ms rise and fall times. The spectrum level of the masker was 30-dB SPL. Thresholds for the backward masked tone were determined adaptively for 6 young adults using a rule that converges on the 71% correct point on the psychometric function. The average threshold was 50-dB SPL (SD=12 dB). Thirteen infants were trained to respond to a backward masked 95-dB SPL tone, but not to the masker alone. These infants then completed 30 single-interval test trials, with 15 no-signal trials and 15 signal trials with the tone fixed at 85-dB SPL and the same backward masker. Infants achieved a p(C)max of about 0.7 (SD=0.05) in this task. These results suggest that at this age infants' backward masked threshold is about 35 dB higher than the adults'.

  2. SEMATECH EUVL mask program status

    NASA Astrophysics Data System (ADS)

    Yun, Henry; Goodwin, Frank; Huh, Sungmin; Orvek, Kevin; Cha, Brian; Rastegar, Abbas; Kearney, Patrick

    2009-04-01

    As we approach the 22nm half-pitch (hp) technology node, the industry is rapidly running out of patterning options. Of the several lithography techniques highlighted in the International Technology Roadmap for Semiconductors (ITRS), the leading contender for the 22nm hp insertion is extreme ultraviolet lithography (EUVL). Despite recent advances with EUV resist and improvements in source power, achieving defect free EUV mask blank and enabling the EUV mask infrastructure still remain critical issues. To meet the desired EUV high volume manufacturing (HVM) insertion target date of 2013, these obstacles must be resolved on a timely bases. Many of the EUV mask related challenges remain in the pre-competitive stage and a collaborative industry based consortia, such as SEMATECH can play an important role to enable the EUVL landscape. SEMATECH based in Albany, NY is an international consortium representing several of the largest manufacturers in the semiconductor market. Full members include Intel, Samsung, AMD, IBM, Panasonic, HP, TI, UMC, CNSE (College of Nanoscience and Engineering), and Fuller Road Management. Within the SEMATECH lithography division a major thrust is centered on enabling the EUVL ecosystem from mask development, EUV resist development and addressing EUV manufacturability concerns. An important area of focus for the SEMATECH mask program has been the Mask Blank Development Center (MBDC). At the MBDC key issues in EUV blank development such as defect reduction and inspection capabilities are actively pursued together with research partners, key suppliers and member companies. In addition the mask program continues a successful track record of working with the mask community to manage and fund critical mask tools programs. This paper will highlight recent status of mask projects and longer term strategic direction at the MBDC. It is important that mask technology be ready to support pilot line development HVM by 2013. In several areas progress has been

  3. EUVL alternating phase shift mask

    NASA Astrophysics Data System (ADS)

    Yan, Pei-Yang; Myers, Alan; Shroff, Yashesh; Chandhok, Manish; Zhang, Guojing; Gullikson, Eric; Salmassi, Farhad

    2011-04-01

    Extreme ultra-violet Lithography (EUVL) alternating phase shift mask (APSM) or other optical enhancement techniques are likely needed for 16nm (half pitch) technology generation and beyond. One possible option is the combination of EUVL and APSM. The fabrication of EUVL APSM is more difficult than either the fabrication of an EUVL binary mask or a conventional optical APSM mask. In the case of EUVL APSM, the phase difference in the two regions (0 and 180-degree phase regions) is created by a phase step in the substrate prior to the multilayer (ML) coating. The step height that induces 180-degree phase mismatch in the ML is determined by [λ/(4cosθ)](2m+1), where m are integers (0, 1, 2,...). In this experiment, we targeted for a step height with m=1. The same mask design also contains the standard binary structures so that the comparison between the EUVL APSM and the EUVL binary mask can be performed under the same illumination and wafer process conditions. The EUVL APSM mask was exposed using Nikon's EUV1 scanner in Kumagaya Japan. The wafer level results showed higher dense line resolution for EUVL APSM as compared to that of EUVL binary mask. APSM also showed improved line width roughness (LWR) and depth of focus (DoF) as compared to the best EUVL binary results obtained with C-dipole off-axis illumination (OAI). The wafer CD resolution improvement obtained by APSM in this experiment is partially limited by the resist resolution and the mask phase edge spread during ML deposition. We believe that wafer CD resolution and can further be improved with imaging imbalance compensation mask design and improvements in resist resolution and the phase generation portion of the mask fabrication process. In this paper, we will discuss in detail the mask fabrication process, wafer level data analysis, and our understanding of EUVL APSM related issues.

  4. Masked Repetition Priming Using Magnetoencephalography

    ERIC Educational Resources Information Center

    Monahan, Philip J.; Fiorentino, Robert; Poeppel, David

    2008-01-01

    Masked priming is used in psycholinguistic studies to assess questions about lexical access and representation. We present two masked priming experiments using MEG. If the MEG signal elicited by words reflects specific aspects of lexical retrieval, then one expects to identify specific neural correlates of retrieval that are sensitive to priming.…

  5. Simplified tooling for spray masking

    NASA Technical Reports Server (NTRS)

    Dinbar, B. J.; Hammons, R. E.

    1978-01-01

    Tooling technique involves positioning tiles within acrylic plastic masking frames that attach magnetically to holding fixture. Plastics are "magnetized" with adhesive mangetic-rubber strips. Technique is simpler and less expensive than conventional methods. L-shaped masks are easily cut and altered.

  6. Defect tolerant transmission lithography mask

    DOEpatents

    Vernon, Stephen P.

    2000-01-01

    A transmission lithography mask that utilizes a transparent substrate or a partially transparent membrane as the active region of the mask. A reflective single layer or multilayer coating is deposited on the membrane surface facing the illumination system. The coating is selectively patterned (removed) to form transmissive (bright) regions. Structural imperfections and defects in the coating have negligible effect on the aerial image of the mask master pattern since the coating is used to reflect radiation out of the entrance pupil of the imaging system. Similarly, structural imperfections in the clear regions of the membrane have little influence on the amplitude or phase of the transmitted electromagnetic fields. Since the mask "discards," rather than absorbs, unwanted radiation, it has reduced optical absorption and reduced thermal loading as compared to conventional designs. For EUV applications, the mask circumvents the phase defect problem, and is independent of the thermal load during exposure.

  7. Energetic and informational masking in a simulated restaurant environment.

    PubMed

    Culling, John F

    2013-01-01

    Participants were seated at a central table for two in a virtual restaurant, simulated over headphones. They listened to the person across the table. Speech reception thresholds (SRTs) were measured as a function of the number of interfering sources distributed across other tables in the room; those sources were either speech-shaped noises or competing speech. The restaurant either was enclosed by acoustically reflective surfaces or was anechoic. Variations in SRT for speech-shaped noises were accurately predicted (r = 0.96) by a model of spatial release from masking based on the additive combination of better-ear listening and binaural unmasking. However, SRTs for interfering voices followed a different pattern. A single interfering voice gave a lower SRT than a single speech-shaped noise source (by 6.3 dB in anechoic conditions and 1.2 dB in reverberant conditions). This difference can be attributed to the effects of dip listening and to the exploitation of differences between voices in fundamental frequency (F0). SRTs for two interfering voices were markedly higher than for a single voice, particularly when the interfering voice was the same as the target voice. Multiple speech interferers produced more masking than multiple noise interferers. This effect can be attributed to informational masking (IM). These results indicate that current models require some elaboration before they will produce accurate predictions of intelligibility in noisy social environments.

  8. An Examination of Speech Recognition in a Modulated Background and of Forward Masking in Younger and Older Listeners

    ERIC Educational Resources Information Center

    Gifford, Rene H.; Bacon, Sid P.; Williams, Erica J.

    2007-01-01

    Purpose: To compare speech intelligibility in the presence of a 10-Hz square-wave noise masker in younger and older listeners and to relate performance to recovery from forward masking. Method: The signal-to-noise ratio required to achieve 50% sentence identification in the presence of a 10-Hz square-wave noise masker was obtained for each of the…

  9. BAYESIAN INSIGHTS ON DISCLOSURE LIMITATION: MASK OR IMPUTE?

    SciTech Connect

    S. KELLER-MCNULTY; G. DUNCAN

    2000-10-01

    Statistical agencies seek to disseminate useful data while keeping low the risk of statistical confidentiality disclosure. Recognizing that reidentification of data is generally inadequate to protect its confidentiality against attack by a data snooper, agencies restrict the data they release for general use. Typically, these restricted data procedures have involved transformation or masking of the original, collected data through such devices as adding noise, topcoding, data swapping, and recoding. Recently, proposals have been put forth for the release of synthetic data, simulated from models constructed from the original data. This paper gives a framework for the comparison of masking and synthetic data as two approaches to disclosure limitation. Particular attention is paid to data utility and disclosure risk. Examples of instantiation of masking and of synthetic data construction are provided to illustrate the concepts. Particular attention is paid to data swapping. Insights drawn from the Bayesian paxadigm are provided.

  10. Effects of Tidal Turbine Noise on Fish Hearing and Tissues - Draft Final Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30

    Snohomish Public Utility District No.1 plans to deploy two 6 meter OpenHydro tidal turbines in Admiralty Inlet in Puget Sound, under a FERC pilot permitting process. Regulators and stakeholders have raised questions about the potential effect of noise from the turbines on marine life. Noise in the aquatic environment is known to be a stressor to many types of aquatic life, including marine mammals, fish and birds. Marine mammals and birds are exceptionally difficult to work with for technical and regulatory reasons. Fish have been used as surrogates for other aquatic organisms as they have similar auditory structures. This project was funded under the FY09 Funding Opportunity Announcement (FOA) to Snohomish PUD, in partnership with the University of Washington - Northwest National Marine Renewable Energy Center, the Sea Mammal Research Unit, and Pacific Northwest National Laboratory. The results of this study will inform the larger research project outcomes. Proposed tidal turbine deployments in coastal waters are likely to propagate noise into nearby waters, potentially causing stress to native organisms. For this set of experiments, juvenile Chinook salmon (Oncorhynchus tshawytscha) were used as the experimental model. Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study was performed during FY 2011 to determine if noise generated by a 6-m diameter OpenHydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. Naturally spawning stocks of Chinook salmon that utilize Puget Sound are listed as threatened (http://www.nwr.noaa

  11. Detection of whale calls in noise: performance comparison between a beluga whale, human listeners, and a neural network.

    PubMed

    Erbe, C

    2000-07-01

    This article examines the masking by anthropogenic noise of beluga whale calls. Results from human masking experiments and a software backpropagation neural network are compared to the performance of a trained beluga whale. The goal was to find an accurate, reliable, and fast model to replace lengthy and expensive animal experiments. A beluga call was masked by three types of noise, an icebreaker's bubbler system and propeller noise, and ambient arctic ice-cracking noise. Both the human experiment and the neural network successfully modeled the beluga data in the sense that they classified the noises in the same order from strongest to weakest masking as the whale and with similar call-detection thresholds. The neural network slightly outperformed the humans. Both models were then used to predict the masking of a fourth type of noise, Gaussian white noise. Their prediction ability was judged by returning to the aquarium to measure masked-hearing thresholds of a beluga in white noise. Both models and the whale identified bubbler noise as the strongest masker, followed by ramming, then white noise. Natural ice-cracking noise masked the least. However, the humans and the neural network slightly overpredicted the amount of masking for white noise. This is neglecting individual variation in belugas, because only one animal could be trained. Comparing the human model to the neural network model, the latter has the advantage of objectivity, reproducibility of results, and efficiency, particularly if the interference of a large number of signals and noise is to be examined.

  12. Noise and Speech Interference: Proceedings of Minisymposium

    NASA Technical Reports Server (NTRS)

    Shepherd, W. T. (Editor)

    1975-01-01

    Several papers are presented which deal with the psychophysical effects of interference with speech and listening activities by different forms of noise masking and filtering. Special attention was given to the annoyance such interruptions cause, particularly that due to aircraft flyover noises. Activities such as telephone listening and television watching were studied. A number of experimental investigations are described and the results are analyzed.

  13. Tuning the cognitive environment: Sound masking with 'natural' sounds in open-plan offices

    NASA Astrophysics Data System (ADS)

    DeLoach, Alana

    With the gain in popularity of open-plan office design and the engineering efforts to achieve acoustical comfort for building occupants, a majority of workers still report dissatisfaction in their workplace environment. Office acoustics influence organizational effectiveness, efficiency, and satisfaction through meeting appropriate requirements for speech privacy and ambient sound levels. Implementing a sound masking system is one tried-and-true method of achieving privacy goals. Although each sound masking system is tuned for its specific environment, the signal -- random steady state electronic noise, has remained the same for decades. This research work explores how `natural' sounds may be used as an alternative to this standard masking signal employed so ubiquitously in sound masking systems in the contemporary office environment. As an unobtrusive background sound, possessing the appropriate spectral characteristics, this proposed use of `natural' sounds for masking challenges the convention that masking sounds should be as meaningless as possible. Through the pilot study presented in this work, we hypothesize that `natural' sounds as sound maskers will be as effective at masking distracting background noise as the conventional masking sound, will enhance cognitive functioning, and increase participant (worker) satisfaction.

  14. Biological Activity of Masked Endotoxin

    PubMed Central

    Schwarz, Harald; Gornicec, Jan; Neuper, Theresa; Parigiani, Maria Alejandra; Wallner, Michael; Duschl, Albert; Horejs-Hoeck, Jutta

    2017-01-01

    Low endotoxin recovery (LER) is a recently discovered phenomenon describing the inability of limulus amebocyte lysate (LAL)-based assays to detect lipopolysaccharide (LPS) because of a “masking effect” caused by chelators or detergents commonly used in buffer formulations for medical products and recombinant proteins. This study investigates the masking capacities of different buffer formulations and whether masked endotoxin is biologically active. We show that both naturally occurring endotoxin as well as control standard endotoxin can be affected by LER. Furthermore, whereas masked endotoxin cannot be detected in Factor C based assays, it is still detectable in a cell-based TLR4-NF-κB-luciferase reporter gene assay. Moreover, in primary human monocytes, masked LPS induces the expression of pro-inflammatory cytokines and surface activation markers even at very low concentrations. We therefore conclude that masked LPS is a potent trigger of immune responses, which emphasizes the potential danger of masked LPS, as it may pose a health threat in pharmaceutical products or compromise experimental results. PMID:28317862

  15. Environmental ground borne noise and vibration protection of sensitive cultural receptors along the Athens Metro Extension to Piraeus.

    PubMed

    Vogiatzis, Konstantinos

    2012-11-15

    Attiko Metro S.A., the state company ensuring the development of the Athens Metro network, has recently initiated a new extension of 7.6 km, has planned for line 3 of Athens Metro from Haidari to Piraeus "Dimotikon Theatre" towards "University of Piraeus" (forestation), connecting the major Piraeus Port with "Eleftherios Venizelos" International Airport. The Piraeus extension consists of a Tunnel Boring Machine, 2 tracks and, tunnel sections, as well as 6 stations and a forestation (New Austrian Tunnelling Method) at the end of the alignment. In order to avoid the degradation of the urban acoustic environment from ground borne noise and vibration during metro operation, the assessment of the required track types and possible noise mitigation measures was executed, and for each section and each sensitive building, the ground borne noise and vibration levels will be numerically predicted. The calculated levels were then compared with ground borne noise and vibration level criteria. The necessary mitigation measures were defined in order to guarantee, in each location along the extension, the allowable ground borne Noise and Vibration max. levels inside nearby sensitive buildings taking into account alternative Transfer Functions for ground borne noise diffusion inside the buildings. Ground borne noise levels were proven to be higher than the criterion where special track work is present and also in the case of the sensitive receptor: "Dimotikon Theatre". In order to reduce the ground borne noise levels to allowable values in these sections, the installation of tracks and special track work on a floating slab was assessed and recommended.

  16. Under-ice ambient noise in Eastern Beaufort Sea, Canadian Arctic, and its relation to environmental forcing.

    PubMed

    Kinda, G Bazile; Simard, Yvan; Gervaise, Cédric; Mars, Jérome I; Fortier, Louis

    2013-07-01

    This paper analyzes an 8-month time series (November 2005 to June 2006) of underwater noise recorded at the mouth of the Amundsen Gulf in the marginal ice zone of the western Canadian Arctic when the area was >90% ice covered. The time-series of the ambient noise component was computed using an algorithm that filtered out transient acoustic events from 7-min hourly recordings of total ocean noise over a [0-4.1] kHz frequency band. Under-ice ambient noise did not respond to thermal changes, but showed consistent correlations with large-scale regional ice drift, wind speed, and measured currents in upper water column. The correlation of ambient noise with ice drift peaked for locations at ranges of ~300 km off the mouth of the Amundsen Gulf. These locations are within the multi-year ice plume that extends westerly along the coast in the Eastern Beaufort Sea due to the large Beaufort Gyre circulation. These results reveal that ambient noise in Eastern Beaufort Sea in winter is mainly controlled by the same meteorological and oceanographic forcing processes that drive the ice drift and the large-scale circulation in this part of the Arctic Ocean.

  17. Environmental impact of electric motorcycles: Evidence from traffic noise assessment by a building-based data mining technique.

    PubMed

    Sheng, N; Zhou, X; Zhou, Y

    2016-06-01

    This study provided new evidence on the potential adoption of electric motorcycle (EM) as a cleaner alternative to gasoline-powered motorcycle. The effects of EM on human exposure to traffic noise were assessed in different urban areas with different traffic scenarios. The assessment was carried out by a developed building-based model system that took into account the contribution of motorcycle traffic. The results indicated that the EM could be an appealing solution to reduce the risk of human exposure to excessive high traffic noise in a motorcycle city. Particularly, in a historical urban area in which the total traffic volume was lower and motorcycle traffic was dominant, the proportion of noise levels meeting the standard of 70 dB(A) increased significantly from 12.2% to 41.9% when 100% of gasoline motorcycles in the real traffic scenario were replaced by EMs. On the other hand, in a modern urban area in which the total traffic volume was higher and traffic noise levels at majority of sites were higher than 75 dB(A), the proportion of noise levels above 75 dB(A) decreased significantly from 82.6% to 59.9%. Nevertheless, the effect of EM on improving the traffic noise compliance rate in the modern urban area was not significant and other policies or measures need to be sought.

  18. Passerine Birds Breeding under Chronic Noise Experience Reduced Fitness

    PubMed Central

    Schroeder, Julia; Nakagawa, Shinichi; Cleasby, Ian R.; Burke, Terry

    2012-01-01

    Background Fitness in birds has been shown to be negatively associated with anthropogenic noise, but the underlying mechanisms remain obscure. It is however crucial to understand the mechanisms of how urban noise impinges on fitness to obtain a better understanding of the role of chronic noise in urban ecology. Here, we examine three hypotheses on how noise might reduce reproductive output in passerine birds: (H1) by impairing mate choice, (H2) by reducing territory quality and (H3) by impeding chick development. Methodology/Principal Findings We used long-term data from an island population of house sparrows, Passer domesticus, in which we can precisely estimate fitness. We found that nests in an area affected by the noise from large generators produced fewer young, of lower body mass, and fewer recruits, even when we corrected statistically for parental genetic quality using a cross-fostering set-up, supporting H3. Also, individual females provided their young with food less often when they bred in the noisy area compared to breeding attempts by the same females elsewhere. Furthermore, we show that females reacted flexibly to increased noise levels by adjusting their provisioning rate in the short term, which suggests that noise may be a causal factor that reduces reproductive output. We rejected H1 and H2 because nestbox occupancy, parental body mass, age and reproductive investment did not differ significantly between noisy and quiet areas. Conclusions/Significance Our results suggest a previously undescribed mechanism to explain how environmental noise can reduce fitness in passerine birds: by acoustically masking parent–offspring communication. More importantly, using a cross-fostering set-up, our results demonstrate that birds breeding in a noisy environment experience significant fitness costs. Chronic noise is omnipresent around human habitation and may produces similar fitness consequences in a wide range of urban bird species. PMID:22808028

  19. Passive acoustic detection and localization of whales: effects of shipping noise in Saguenay-St. Lawrence Marine Park.

    PubMed

    Simard, Yvan; Roy, Nathalie; Gervaise, Cédric

    2008-06-01

    The performance of large-aperture hydrophone arrays to detect and localize blue and fin whales' 15-85 Hz signature vocalizations under ocean noise conditions was assessed through simulations from a normal mode propagation model combined to noise statistics from 15 960 h of recordings in Saguenay-St. Lawrence Marine Park. The probability density functions of 2482 summer noise level estimates in the call bands were used to attach a probability of detection/masking to the simulated call levels as a function of whale depth and range for typical environmental conditions. Results indicate that call detection was modulated by the calling depth relative to the sound channel axis and by modal constructive and destructive interferences with range. Masking of loud infrasounds could reach 40% at 30 km for a receiver at the optimal depth. The 30 dB weaker blue whale D-call were subject to severe masking. Mapping the percentages of detection and localization allowed assessing the performance of a six-hydrophone array under mean- and low-noise conditions. This approach is helpful for optimizing hydrophone configuration in implementing passive acoustic monitoring arrays and building their detection function for whale density assessment, as an alternative to or in combination with the traditional undersampling visual methods.

  20. Hg-Mask Coronagraph

    NASA Astrophysics Data System (ADS)

    Bourget, P.; Veiga, C. H.; Vieira Martins, R.; Assus, P.; Colas, F.

    In order to optimize the occulting process of a Lyot coronagraph and to provide a high dynamic range imaging, a new kind of occulting disk has been developed at the National Observatory of Rio de Janeiro. A mercury (Hg) drop glued onto an optical window by molecular cohesion and compressed by a pellicle film is used as the occulting disk. The minimum of the superficial tension potential function provides an optical precision (lambda/100) of the toric free surface of the mercury. This process provides a size control for the adaptation to the seeing conditions and to the apparent diameter of a resolved object, and in the case of adaptive optics, to the Airy diameter fraction needed. The occultation is a three dimensional process near the focal plane on the toric free surface that provides an apodization of the occultation. The Hg-Mask coronagraph has been projected for astrometric observations of faint satellites near to Jovian planets and works since 2000 at the 1.6 m telescope of the Pico dos Dias Observatory (OPD - Brazil).

  1. Mechanical alignment of substrates to a mask

    SciTech Connect

    Webb, Aaron P.; Carlson, Charles T.; Honan, Michael; Amato, Luigi G.; Grant, Christopher Neil; Strassner, James D.

    2016-11-08

    A plurality of masks is attached to the underside of a mask frame. This attachment is made such that each mask can independently move relative to the mask frame in three directions. This relative movement allows each mask to adjust its position to align with respective alignment pins disposed on a working surface. In one embodiment, each mask is attached to the mask frame using fasteners, where the fasteners have a shaft with a diameter smaller than the diameter of the mounting hole disposed on the mask. A bias element may be used to allow relative movement between the mask and the mask frame in the vertical direction. Each mask may also have kinematic features to mate with the respective alignment pins on the working surface.

  2. Electron Beam Pattern Writer For X-Ray Masks

    NASA Astrophysics Data System (ADS)

    Viswanathan, R.; Wilson, A. D.; Lafuente, J.; Voelker, H.; Kern, A.

    1984-03-01

    This paper discusses the capabilities of a vector scan electron-beam system as an X-ray mask writer for pattern geometries at and below one-half micron. The noise level in the deflection system has been reduced to an RMS value of 150 A over a 0.5 mm deflection field, thus making our exposure system usable in the one-quarter micron regime. Pattern geometries below 2000 A have been fabricated on a thin membrane. Drift compensation techniques, implemented in software, have reduced placement errors over the entire mask to less than 700 A. Accomplishments in the areas of noise reduction, bandwidth error compensation, system resolution, and improvements in pattern placement accuracy are discussed.

  3. Remote sensing of cirrus cloud optical thickness and effective particle size for the National Polar-orbiting Operational Environmental Satellite System Visible/Infrared Imager Radiometer Suite: sensitivity to instrument noise and uncertainties in environmental parameters.

    PubMed

    Ou, Szu-Cheng; Takano, Yoshihide; Liou, K N; Higgins, Glenn J; George, Adrian; Slonaker, Richard

    2003-12-20

    We describe sensitivity studies on the remote sensing of cirrus cloud optical thickness and effective particle size using the National Polar-orbiting Operational Environmental Satellite System Visible/Infrared Imager Radiometer Suite 0.67-, 1.24-, 1.61-, and 2.25-microm reflectances and thermal IR 3.70- and 10.76-microm radiances. To investigate the accuracy and precision of the solar and IR retrieval methods subject to instrument noise and uncertainties in environmental parameters, we carried out signal-to-noise ratio tests as well as the error budget study, where we used the University of California at Los Angeles line-by-line equivalent radiative transfer model to generate radiance tables for synthetic retrievals. The methodology and results of these error analyses are discussed.

  4. Scanning coherent scattering methods for actinic EUV mask inspection

    NASA Astrophysics Data System (ADS)

    Ekinci, Y.; Helfenstein, P.; Rajeev, R.; Mochi, I.; Mohacsi, I.; Gobrecht, J.; Yoshitake, S.

    2016-10-01

    Actinic mask inspection for EUV lithography with targeted specifications of resolution, sensitivity, and throughput remains a big hurdle for the successful insertion of EUVL into high volume manufacturing and effective solutions are needed to address this. We present a method for actinic mask inspection based on scanning coherent scattering microscopy. In this method, the mask is scanned with an EUV beam of relatively small spot size and the scattered light is recorded with a pixel detector. Customized algorithms reconstruct the aerial image by iteratively solving the phaseproblem using over-determined diffraction data gathered by scanning across the specimen with a finite illumination. This approach provides both phase and amplitude of actinic aerial images of the mask with high resolution without the need to use high NA (numerical aperture) lenses. Futher, we describe a reflective mode EUV mask scanning lensless imaging tool (RESCAN), which was installed at the XIL-II beamline and later at the SIM beamline of the Swiss Light Source and show reconstructed aerial images down to 10 nm (on-wafer) resolution. As a complementary method, the a-priori knowledge of the sample is employed to identify potential defect sites by analyzing the diffraction patterns. In this method, the recorded diffraction patterns are compared with the die or database data (i.e. previously measured or calculated diffraction data from the defect-free mask layout respectively) and their difference is interpreted as the defect signal. Dynamic software filtering helps to suppress the strong diffraction from defect-free structures and allows registration of faint defects with high sensitivity. Here, we discuss the basic principles of these Fourier domain techniques and its potential for actinic mask inspection with high signal-to-noise ratio and high throughput.

  5. Developmental Effects in the Masking-Level Difference

    ERIC Educational Resources Information Center

    Hall, Joseph W.; Buss, Emily; Grose, John H.; Dev, Madhu B.

    2004-01-01

    Adults and children (aged 5 years 1 month to 10 years 8 months) were tested in a masking-level difference (MLD) paradigm in which detection of brief signals was contrasted for signal placement in masker envelope maxima versus masker envelope minima. Maskers were 50-Hz-wide noise bands centered on 500 Hz, and the signals were So or S[pi] 30-ms,…

  6. Vibrotactile masking through the body.

    PubMed

    D'Amour, Sarah; Harris, Laurence R

    2014-09-01

    Touches on one hand or forearm can affect tactile sensitivity at contralateral locations on the opposite side of the body. These interactions suggest an intimate connection between the two sides of the body. Here, we explore the effect of masking not across the body but through the body by measuring the effect of a masking stimulus on the back on the tactile sensitivity of the corresponding point on the front. Tactile sensitivity was measured on each side of the stomach, while vibrotactile masking stimulation was applied to one side of the front and to points on the back including the point directly behind the test point on the front. Results were compared to sensitivity, while vibrotactile stimulation was applied to a control site on the shoulder. A reduction in sensitivity of about .8 dB was found that required the masking stimulus to be within about 2 cm of the corresponding point on the back.

  7. Coherent diffractive imaging using randomly coded masks

    SciTech Connect

    Seaberg, Matthew H.; D'Aspremont, Alexandre; Turner, Joshua J.

    2015-12-07

    We experimentally demonstrate an extension to coherent diffractive imaging that encodes additional information through the use of a series of randomly coded masks, removing the need for typical object-domain constraints while guaranteeing a unique solution to the phase retrieval problem. Phase retrieval is performed using a numerical convex relaxation routine known as “PhaseCut,” an iterative algorithm known for its stability and for its ability to find the global solution, which can be found efficiently and which is robust to noise. The experiment is performed using a laser diode at 532.2 nm, enabling rapid prototyping for future X-ray synchrotron and even free electron laser experiments.

  8. Subdivisions with infinitely supported mask

    NASA Astrophysics Data System (ADS)

    Li, Song; Pan, Yali

    2008-04-01

    In this paper we investigate the convergence of subdivision schemes associated with masks being polynomially decay sequences. Two-scale vector refinement equations are the formwhere the vector of functions [phi]=([phi]1,E..,[phi]r)T is in and is polynomially decay sequence of rxr matrices called refinement mask. Associated with the mask a is a linear operator on given byBy using same methods in [B. Han, R. Q. Jia, Characterization of Riesz bases of wavelets generated from multiresolution analysis, manuscript]; [BE Han, Refinable functions and cascade algorithms in weighted spaces with infinitely supported masks, manuscript]; [R.Q. Jia, Q.T. Jiang, Z.W. Shen, Convergence of cascade algorithms associated with nonhomogeneous refinement equations, Proc. Amer. Math. Soc. 129 (2001) 415-427]; [R.Q. Jia, Convergence of vector subdivision schemes and construction of biorthogonal multiple wavelets, in: Advances in Wavelet, Hong Kong,1997, Springer, Singapore, 1998, pp. 199-227], a characterization of convergence of the sequences in the L2-norm is given, which extends the main results in [R.Q. Jia, S.D. Riemenschneider, D.X. Zhou, Vector subdivision schemes and multiple wavelets, Math. Comp. 67 (1998) 1533-1563] on convergence of the subdivision schemes associated with a finitely supported mask to the case in which mask a is polynomially decay sequence. As an application, we also obtain a characterization of smoothness of solutions of the refinement equation mentioned above for the case r=1.

  9. Simple model for spatial-frequency masking and contrast discrimination

    NASA Astrophysics Data System (ADS)

    Barten, Peter G. J.

    1995-04-01

    After some principal considerations about noise and the psychometric function,we present a model for the masking of a spatial frequency patten by nonwhite noise. From threshold elevation measurements by Stromeyer and Julesz, we derive a distribution function for the disturbing effect of one frequency on the detection of another frequency. We apply the resulting formulas on contrast sensitivity measurements with nonwhite noise by van Meeteren and Valeton. Next we use the same principles to derive a simple model for contrast discrimination. We consider the pedestal modulation as a nonwhite noise source of a single spatial frequency that hampers contrast detection. We show that contrast discrimination plots for different spatial frequencies will coincide if they are plotted in a normalized way. After a slight practical correction the model appears to be in very good agreement with measurements of various authors published in literature.

  10. Noise Hazard Evaluation Sound Level Data on Noise Sources

    DTIC Science & Technology

    1975-01-01

    AD-A021 465 NOISE HAZARD EfALUATION SOUND LEVEL DATA ON NOISE SOURCES Jeffrey Goldstein Army Environmental Hygiene Agency Prepared for: Army Health ...A. Noise Hazard Evaluation. B. Engineering Noise Control. C. Health Education. D. Audiometry. E. Hearing Protection. This technical guide concerns the...SOUND LEVEL DATA OF NOISE SOURCES Approved for public release, distribution unlimited. jGI4A C4C SENTINEL HEALTH I 5 US ARMY ENVIROIN.MENTAL HYGIENE

  11. Visual Masking During Pursuit Eye Movements

    ERIC Educational Resources Information Center

    White, Charles W.

    1976-01-01

    Visual masking occurs when one stimulus interferes with the perception of another stimulus. Investigates which matters more for visual masking--that the target and masking stimuli are flashed on the same part of the retina, or, that the target and mask appear in the same place. (Author/RK)

  12. Unmasking the effects of masking on performance: The potential of multiple-voice masking in the office environment.

    PubMed

    Keus van de Poll, Marijke; Carlsson, Johannes; Marsh, John E; Ljung, Robert; Odelius, Johan; Schlittmeier, Sabine J; Sundin, Gunilla; Sörqvist, Patrik

    2015-08-01

    Broadband noise is often used as a masking sound to combat the negative consequences of background speech on performance in open-plan offices. As office workers generally dislike broadband noise, it is important to find alternatives that are more appreciated while being at least not less effective. The purpose of experiment 1 was to compare broadband noise with two alternatives-multiple voices and water waves-in the context of a serial short-term memory task. A single voice impaired memory in comparison with silence, but when the single voice was masked with multiple voices, performance was on level with silence. Experiment 2 explored the benefits of multiple-voice masking in more detail (by comparing one voice, three voices, five voices, and seven voices) in the context of word processed writing (arguably a more office-relevant task). Performance (i.e., writing fluency) increased linearly from worst performance in the one-voice condition to best performance in the seven-voice condition. Psychological mechanisms underpinning these effects are discussed.

  13. Noise Abatement

    NASA Technical Reports Server (NTRS)

    1983-01-01

    SMART, Sound Modification and Regulated Temperature compound, is a liquid plastic mixture with exceptional energy and sound absorbing qualities. It is derived from a very elastic plastic which was an effective noise abatement material in the Apollo Guidance System. Discovered by a NASA employee, it is marketed by Environmental Health Systems, Inc. (EHS). The product has been successfully employed by a diaper company with noisy dryers and a sugar company with noisy blowers. The company also manufactures an audiometric test booth and acoustical office partitions.

  14. Real-time natural soundscape generation based on current weather conditions for workspace voice-masking

    NASA Astrophysics Data System (ADS)

    Riggs, Caitlin

    Sound masking in work spaces has been implemented to decrease likelihood of distraction from work tasks and improve speech privacy. Current uses of noise as maskers commonly apply broadband white or pink noise signals due to their perceived neutrality. This research combines work into the restorative properties of exposure to nature/natural sounds and pilot studies of natural sounds as maskers to suggest a noise-masking system of 'natural' sounds. This system composes a natural soundscape in real time determined by the current weather and time of day such that the masking audio is aesthetically pleasing and informative about the outside world in addition to providing improved speech privacy and reducing distraction when compared to a setting with no masking system. Currently there is no experimental foundation to suggest that restoration or slowed attentional fatigue can occur if this type of alternative masking sound is presented during a task. This implementation of a dynamic, immersive soundscape masker begins the investigation into the practical efficacy of such a masking system.

  15. Environmental stressors and cardio-metabolic disease: part I-epidemiologic evidence supporting a role for noise and air pollution and effects of mitigation strategies.

    PubMed

    Münzel, Thomas; Sørensen, Mette; Gori, Tommaso; Schmidt, Frank P; Rao, Xiaoquan; Brook, Jeffrey; Chen, Lung Chi; Brook, Robert D; Rajagopalan, Sanjay

    2016-07-26

    Traffic noise and air pollution together represent the two most important environmental risk factors in urbanized societies. The first of this two-part review discusses the epidemiologic evidence in support of the existence of an association between these risk factors with cardiovascular and metabolic disease. While independent effects of these risk factors have now clearly been shown, recent studies also suggest that the two exposures may interact with each other and with traditional risk factors such as hypertension and type 2 diabetes. From a societal and policy perspective, the health effects of both air pollution and traffic noise are observed for exposures well below the thresholds currently accepted as being safe. Current gaps in knowledge, effects of intervention and their impact on cardiovascular disease, will be discussed in the last section of this review. Increased awareness of the societal burden posed by these novel risk factors and acknowledgement in traditional risk factor guidelines may intensify the efforts required for effective legislation to reduce air pollution and noise.

  16. Contralateral tactile masking between forearms.

    PubMed

    D'Amour, Sarah; Harris, Laurence R

    2014-03-01

    Masking effects have been demonstrated in which tactile sensitivity is affected when one touch is close to another on the body surface. Such effects are likely a result of local lateral inhibitory circuits that sharpen the spatial tuning of a given tactile receptor. Mutually inhibitory pathways have also been demonstrated between cortical tactile maps of the two halves of the body. Occasional reports have indicated that touches on one hand or forearm can affect tactile sensitivity at contralateral locations. Here, we measure the spatial tuning and effect of posture on this contralateral masking effect. Tactile sensitivity was measured on one forearm, while vibrotactile masking stimulation was applied to the opposite arm. Results were compared to sensitivity while vibrotactile stimulation was applied to a control site on the right shoulder. Sensitivity on the forearm was reduced by over 3 dB when the arms were touching and by 0.52 dB when they were held parallel. The masking effect depended on the position of the masking stimulus. Its effectiveness fell off by 1 STD when the stimulus was 29 % of arm length from the corresponding contralateral point. This long-range inhibitory effect in the tactile system suggests a surprisingly intimate relationship between the two sides of the body.

  17. Anthropogenic noise is associated with reductions in the productivity of breeding Eastern Bluebirds (Sialia sialis).

    PubMed

    Kight, Caitlin R; Saha, Margaret S; Swaddle, John P

    2012-10-01

    Although previous studies have related variations in environmental noise levels with alterations in communication behaviors of birds, little work has investigated the potential long-term implications of living or breeding in noisy habitats. However, noise has the potential to reduce fitness, both directly (because it is a physiological stressor) and indirectly (by masking important vocalizations and/or leading to behavioral changes). Here, we quantified acoustic conditions in active breeding territories of male Eastern Bluebirds (Sialia sialis). Simultaneously, we measured four fitness indicators: cuckoldry rates, brood growth rate and condition, and number of fledglings produced (i.e., productivity). Increases in environmental noise tended to be associated with smaller brood sizes and were more strongly related to reductions in productivity. Although the mechanism responsible for these patterns is not yet clear, the breeding depression experienced by this otherwise disturbance-tolerant species indicates that anthropogenic noise may have damaging effects on individual fitness and, by extraction, the persistence of populations in noisy habitats. We suggest that managers might protect avian residents from potentially harmful noise by keeping acoustically dominant anthropogenic habitat features as far as possible from favored songbird breeding habitats, limiting noisy human activities, and/or altering habitat structure in order to minimize the propagation of noise pollution.

  18. Optical image encryption technique based on deterministic phase masks

    NASA Astrophysics Data System (ADS)

    Zamrani, Wiam; Ahouzi, Esmail; Lizana, Angel; Campos, Juan; Yzuel, María J.

    2016-10-01

    The double-random phase encoding (DRPE) scheme, which is based on a 4f optical correlator system, is considered as a reference for the optical encryption field. We propose a modification of the classical DRPE scheme based on the use of a class of structured phase masks, the deterministic phase masks. In particular, we propose to conduct the encryption process by using two deterministic phase masks, which are built from linear combinations of several subkeys. For the decryption step, the input image is retrieved by using the complex conjugate of the deterministic phase masks, which were set in the encryption process. This concept of structured masks gives rise to encryption-decryption keys which are smaller and more compact than those required in the classical DRPE. In addition, we show that our method significantly improves the tolerance of the DRPE method to shifts of the decrypting phase mask-when no shift is applied, it provides similar performance to the DRPE scheme in terms of encryption-decryption results. This enhanced tolerance to the shift, which is proven by providing numerical simulation results for grayscale and binary images, may relax the rigidity of an encryption-decryption experimental implementation setup. To evaluate the effectiveness of the described method, the mean-square-error and the peak signal-to-noise ratio between the input images and the recovered images are calculated. Different studies based on simulated data are also provided to highlight the suitability and robustness of the method when applied to the image encryption-decryption processes.

  19. The attentional blink is not affected by backward masking of T2, T2-mask SOA, or level of T2 impoverishment.

    PubMed

    Jannati, Ali; Spalek, Thomas M; Lagroix, Hayley E P; Di Lollo, Vincent

    2012-02-01

    Identification of the second of two targets (T2) is impaired when presented shortly after the first (T1). This attentional blink (AB) is thought to arise from a delay in T2 processing during which T2 is vulnerable to masking. Conventional studies have measured T2 accuracy which is constrained by the 100% ceiling. We avoided this problem by using a dynamic threshold-tracking procedure that is inherently free from ceiling constraints. In two experiments we examined how AB magnitude is affected by three masking-related factors: (a) presence/absence of T2 mask, (b) T2-mask stimulus onset asynchrony (SOA), and (c) level of T2 impoverishment (signal-to-noise ratio [SNR]). In Experiment 1, overall accuracy decreased with T2-mask SOA. The magnitude of the AB, however, was invariant with SOA and with mask presence/absence. Experiment 2 further showed that the AB was invariant with T2 SNR. The relationship among mask presence/absence, SOA, and T2 SNR and the AB is encompassed in a qualitative model.

  20. Very loud speech over simulated environmental noise tends to have a spectral peak in the F1 region

    NASA Astrophysics Data System (ADS)

    Ternstrom, Sten; Bohman, Mikael; Sodersten, Maria

    2003-04-01

    In some professions, workplace noise appears to be a hazard to the voice, if not to hearing. Several studies have shown that teachers and sports instructors, for example, are more prone to voice problems than average, prompting research on loud voice. Since on-location recordings are in many ways impractical, the running speech of 23 untrained speaker subjects (12 female, 11 male) was instead recorded in several types of loud noise that was presented over high-quality loudspeakers. Using adaptive cancellation techniques, the noise was then removed from the recordings, thus exposing the strained voices for analysis. The experiment produced a large body of data, only one aspect of which is reported here. In most subjects, the vowel spectrum as a function of voice SPL showed the expected behavior for low to moderate efforts, but developed a very pronounced peak in the F1 region at the highest efforts. This peak can be ascribed to the concerted action of several acoustic mechanisms, including source waveform asymmetry, F1 approximating one of the lower partials, and increased formant Q values due to a longer closed phase. [Work supported by the Swedish Council for Working Life and Social Research, Contract No. 2001-0341.

  1. Coatings on reflective mask substrates

    SciTech Connect

    Tong, William Man-Wai; Taylor, John S.; Hector, Scott D.; Mangat, Pawitter J. S.; Stivers, Alan R.; Kofron, Patrick G.; Thompson, Matthew A.

    2002-01-01

    A process for creating a mask substrate involving depositing: 1) a coating on one or both sides of a low thermal expansion material EUVL mask substrate to improve defect inspection, surface finishing, and defect levels; and 2) a high dielectric coating, on the backside to facilitate electrostatic chucking and to correct for any bowing caused by the stress imbalance imparted by either other deposited coatings or the multilayer coating of the mask substrate. An film, such as TaSi, may be deposited on the front side and/or back of the low thermal expansion material before the material coating to balance the stress. The low thermal expansion material with a silicon overlayer and a silicon and/or other conductive underlayer enables improved defect inspection and stress balancing.

  2. Impact of mask CDU and local CD variation on intra-field CDU

    NASA Astrophysics Data System (ADS)

    Miyazaki, Junji; Mouraille, Orion; Finders, Jo; Higuchi, Masaru; Kojima, Yosuke; Sato, Shunsuke; Morimoto, Hiroaki

    2012-11-01

    The control of critical dimension uniformity (CDU), especially intra-field CDU, is an important aspect for advanced lithography, and this property must be controlled very tightly since it affects all of the exposure fields. It is well known that the influence of the mask CDU on the wafer intra-field CDU is becoming dominant because the mask error enhancement factor (MEEF) is quite high for low-k1 lithography. Additionally, the abovementioned factors impact the CDU through global (field-level) and local (grating-level) variations. In this paper, we analyze in detail CDU budgets by clarifying the impact of local CD variation. The 50-nm staggered hole features using Att-PSM showed a mask global CDU of 1.64 nm (3sigma at the mask level) and a wafer intra-field CDU of 2.30 nm, indicating that the mask global CDU was a major part of the intra-field CDU. By compensating for the contribution of the mask CD, the wafer intra-field CDU can be reduced to 0.986 nm. We analyzed the budgets of wafer intra-field CDU, which is caused by local CD variation (mask and process) and measurement noise. We determined that a primary cause of the wafer intra-field CDU after applying a mask CD correction was these local CD variations, which might disturb the proper use of dose correction for the mask CD. We demonstrated that the impact of mask local CD variation on the correction flow can be greatly reduced by averaging multiple point measurements within a small area, and therefore discuss the optimum conditions allowing for an accurate intra-field CDU determination. We also consider optimization of the CD sampling scheme in order to apply a dose correction on an exposure system to compensate for the mask CDU.

  3. Production mask composition checking flow

    NASA Astrophysics Data System (ADS)

    Ma, Shou-Yuan; Yang, Chuen-Huei; Tsai, Joe; Wang, Alice; Lin, Roger; Lee, Rachel; Deng, Erwin; Lin, Ling-Chieh; Liao, Hung-Yueh; Tsai, Jenny; Bowhill, Amanda; Vu, Hien; Russell, Gordon

    2016-05-01

    The mask composition checking flow is an evolution of the traditional mask rule check (MRC). In order to differentiate the flow from MRC, we call it Mask Data Correctness Check (MDCC). The mask house does MRC only to identify process limitations including writing, etching, metrology, etc. There still exist many potential errors that could occur when the frame, main circuit and dummies all together form a whole reticle. The MDCC flow combines the design rule check (DRC) and MRC concepts to adapt to the complex patterns in today's wafer production technologies. Although photomask data has unique characteristics, the MRC tool in Calibre® MDP can easily achieve mask composition by using the Extended MEBES job deck (EJB) format. In EJB format, we can customize the combination of any input layers in an IC design layout format, such as OASIS. Calibre MDP provides section-based processing for many standard verification rule format (SVRF) commands that support DRC-like checks on mask data. Integrating DRC-like checking with EJB for layer composition, we actually perform reticle-level DRC, which is the essence of MDCC. The flow also provides an early review environment before the photomask pattern files are available. Furthermore, to incorporate the MDCC in our production flow, runtime is one of the most important indexes we consider. When the MDCC is included in the tape-out flow, the runtime impact is very limited. Calibre, with its multi-threaded processes and good scalability, is the key to achieving acceptable runtime. In this paper, we present real case runtime data for 28nm and 14nm technology nodes, and prove the practicability of placing MDCC into mass production.

  4. Developmental Conductive Hearing Loss Reduces Modulation Masking Release

    PubMed Central

    Chen, Yi-Wen; Sanes, Dan H.

    2016-01-01

    Hearing-impaired individuals experience difficulties in detecting or understanding speech, especially in background sounds within the same frequency range. However, normally hearing (NH) human listeners experience less difficulty detecting a target tone in background noise when the envelope of that noise is temporally gated (modulated) than when that envelope is flat across time (unmodulated). This perceptual benefit is called modulation masking release (MMR). When flanking masker energy is added well outside the frequency band of the target, and comodulated with the original modulated masker, detection thresholds improve further (MMR+). In contrast, if the flanking masker is antimodulated with the original masker, thresholds worsen (MMR−). These interactions across disparate frequency ranges are thought to require central nervous system (CNS) processing. Therefore, we explored the effect of developmental conductive hearing loss (CHL) in gerbils on MMR characteristics, as a test for putative CNS mechanisms. The detection thresholds of NH gerbils were lower in modulated noise, when compared with unmodulated noise. The addition of a comodulated flanker further improved performance, whereas an antimodulated flanker worsened performance. However, for CHL-reared gerbils, all three forms of masking release were reduced when compared with NH animals. These results suggest that developmental CHL impairs both within- and across-frequency processing and provide behavioral evidence that CNS mechanisms are affected by a peripheral hearing impairment. PMID:28215119

  5. Auditory Sensitivity and Masking Profiles for the Sea Otter (Enhydra lutris).

    PubMed

    Ghoul, Asila; Reichmuth, Colleen

    2016-01-01

    Sea otters are threatened marine mammals that may be negatively impacted by human-generated coastal noise, yet information about sound reception in this species is surprisingly scarce. We investigated amphibious hearing in sea otters by obtaining the first measurements of absolute sensitivity and critical masking ratios. Auditory thresholds were measured in air and underwater from 0.125 to 40 kHz. Critical ratios derived from aerial masked thresholds from 0.25 to 22.6 kHz were also obtained. These data indicate that although sea otters can detect underwater sounds, their hearing appears to be primarily air adapted and not specialized for detecting signals in background noise.

  6. The man in the mask.

    PubMed

    Zugibe, F T; Costello, J T; Breithaupt, M K

    1987-05-01

    A skeletonized body, wearing a black leather bondage mask, was found in a Revolutionary War smokehouse cave with two bullet holes in the back of the head. The body was skeletonized up to the maxillary area but the head region under the mask was well preserved and permitted a positive visual identification. There was evidence that the body had been eaten by small animals and subsequently burned. Investigations into this brutal murder revealed a tale of a bizarre sadomasochistic ritual that attained national prominence.

  7. Aperture masking interferometry research simulation

    NASA Astrophysics Data System (ADS)

    Wang, Haitao; Luo, Qiufeng; Fan, Weijun; Zhang, Xian Ling; Tao, Chunkan; Zhu, Yongtian; Zhou, Bifang; Chen, Hanliang

    2004-10-01

    Aperture Masking Interferometry (AMI) is one of the high-resolution astronomical image observation technologies. It is also an important research way to the Optical Aperture Synthesis (OAS). The theory of OAS is simply introduced and AMI simulation method is raised. The mathematics model is built and the interferogram fringes are got. The aperture mask u-v coverage is discussed and one image reconstruction method is done. The reconstructed image result is got with CLEAN method. Shortcoming of this work is also referred and the future research work is mentioned at last.

  8. Ambient Noise in an Urbanized Tidal Channel

    NASA Astrophysics Data System (ADS)

    Bassett, Christopher

    levels that shows good agreement with 85% of the temporal data. Bed stresses associated with currents can produce propagating ambient noise by mobilizing sediments. The strength of the tidal currents in northern Admiralty Inlet produces bed stresses in excess of 20 Pa. Significant increases in noise levels at frequencies from 4-30 kHz, with more modest increases noted from 1-4 kHz, are attributed to mobilized sediments. Sediment-generated noise during strong currents masks background noise from other sources, including vessel traffic. Inversions of the acoustic spectra for equivalent grain sizes are consistent with qualitative observations of the seabed composition. Bed stress calculations using log layer, Reynolds stress, and inertial dissipation techniques generally agree well and are used to estimate the shear stresses at which noise levels increase for different grain sizes. Ambient noise levels in one-third octave bands with center frequencies from 1 kHz to 25 kHz are dominated by sediment-generated noise and can be accurately predicted using the near-bed current velocity above a critical threshold. When turbulence is advected over a pressure sensitive transducer, the turbulent pressure fluctuations can be measured as noise, though these pressure fluctuations are not propagating sound and should not be interpreted as ambient noise. Based on measurements in both Admiralty Inlet, Puget Sound and the Chacao Channel, Chile, two models are developed for flow-noise. The first model combined measurements of mean current velocities and turbulence and agrees well with data from both sites. The second model uses scaling arguments to model the flow-noise based solely on the mean current velocity. This model agrees well with the data from the Chacao Channel but performs poorly in Admiralty Inlet, a difference attributed to differences turbulence production mechanisms. At both sites, the spectral slope of flow noise follows a f-3.2 dependence, suggesting partial cancellation of

  9. Rotorcraft noise

    NASA Technical Reports Server (NTRS)

    Huston, R. J. (Compiler)

    1982-01-01

    The establishment of a realistic plan for NASA and the U.S. helicopter industry to develop a design-for-noise methodology, including plans for the identification and development of promising noise reduction technology was discussed. Topics included: noise reduction techniques, scaling laws, empirical noise prediction, psychoacoustics, and methods of developing and validing noise prediction methods.

  10. The effect of masking noise on rippled-spectrum resolution.

    PubMed

    Supin, A Y; Popov, V V; Milekhina, O N; Tarakanov, M B

    2001-01-01

    Ripple-density resolution in a rippled sound spectrum (probe band) under the effect of another band (masker) was studied in normal listeners. The resolvable ripple density in the probe band was measured using a phase-reversal test. The principle of the test was to find the highest ripple density at which an interchange of mutual peak and valley position (the ripple phase reversal) was detectable. Probe bands were 0.5 octave (oct) wide with center frequencies of 1, 2, and 4 kHz. When a masker band was below the probe one (a low-frequency masker), it markedly reduced the ripple-density resolution. The effect of the low-frequency masker enhanced (ripple-density resolution decreased) with decreasing the stop-band (frequency spacing) between the probe and masker bands. The strongest masker effect was observed at zero spacing between the probe and masker bands. However, when the probe band overlapped the masker one so that no masker power was below the probe band, the masker effect diminished (ripple-density resolution partially released). Increase of the masker bandwidth above 0.5 oct by shifting its lower boundary downwards did not enhance the masker effect. Masker bands above the probe one (high-frequency maskers) did not influence the ripple-density resolution.

  11. Northern elephant seal field bioacoustics and aerial auditory masked hearing thresholds in three pinnipeds

    NASA Astrophysics Data System (ADS)

    Southall, Brandon Lee

    This dissertation comprises four interrelated studies on acoustic communication (including both signal production and signal reception) in pinnipeds, primarily northern elephant seals (Mirounga angustirostris). Field measurements of vocalization parameters were obtained in elephant seal breeding rookeries. Additionally, auditory masking experiments were conducted with individuals representing three pinniped species, including a northern elephant seal. This study quantified how aerial noise masks aerial hearing and provided preliminary data on auditory frequency filtering. All of these studies were conducted in air for a variety of practical and theoretical reasons. Some governmental, media, and research organizations have recently become concerned with the impacts of underwater anthropogenic noise on aquatic animals. However, little consideration has been given to the dual pressures imposed by aerial and underwater noise on amphibious marine mammals such as the pinnipeds. This dissertation sought to provide some basic data bearing on this matter by investigating aerial signals and aerial masked hearing. Data were obtained on aerial vocalization source levels, signal directivity patterns, natural aerial ambient noise, signal propagation properties, multi-modal aspects of signaling, motivation-specific signal variability, aerial critical masking ratios, and auditory filter bandwidths. The results indicate that different signal components may be more readily detectable in variable noise conditions, frequency resolution likely affects detection ranges, developmental and motivational factors affect signal parameters, and that some pinnipeds apparently detect signals over masking noise relatively well both in air and water. Using the northern elephant seal as a representative model, a model for quantifying constraints on vocal communication was developed to provide first-order predictions about detection ranges for signals in variable noise conditions.

  12. Auditory masking in three pinnipeds: Aerial critical ratios and direct critical bandwidth measurements

    NASA Astrophysics Data System (ADS)

    Southall, Brandon L.; Schusterman, Ronald J.; Kastak, David

    2003-09-01

    This study expands the limited understanding of pinniped aerial auditory masking and includes measurements at some of the relatively low frequencies predominant in many pinniped vocalizations. Behavioral techniques were used to obtain aerial critical ratios (CRs) within a hemianechoic chamber for a northern elephant seal (Mirounga angustirostris), a harbor seal (Phoca vitulina), and a California sea lion (Zalophus californianus). Simultaneous, octave-band noise maskers centered at seven test frequencies (0.2-8.0 kHz) were used to determine aerial CRs. Narrower and variable bandwidth masking noise was also used in order to obtain direct critical bandwidths (CBWs). The aerial CRs are very similar in magnitude and in frequency-specific differences (increasing gradually with test frequency) to underwater CRs for these subjects, demonstrating that pinniped cochlear processes are similar both in air and water. While, like most mammals, these pinniped subjects apparently lack specialization for enhanced detection of specific frequencies over masking noise, they consistently detect signals across a wide range of frequencies at relatively low signal-to-noise ratios. Direct CBWs are 3.2 to 14.2 times wider than estimated based on aerial CRs. The combined masking data are significant in terms of assessing aerial anthropogenic noise impacts, effective aerial communicative ranges, and amphibious aspects of pinniped cochlear mechanics.

  13. Non-conscious modulation of cardiac defense by masked phobic pictures.

    PubMed

    Ruiz-Padial, Elisabeth; Mata, José Luís; Rodríguez, Sonia; Fernández, María Carmen; Vila, Jaime

    2005-06-01

    The present study investigated the modulation of cardiac defense by presenting emotional pictures under both effective and non-effective masking procedures. The aim was to test Ohman's model of pre-attentive processing of fear. Participants were 48 women volunteers with intense fear of spiders. The stimulus to elicit cardiac defense was a white noise of 105 dB, 500 ms duration and instantaneous risetime. Subjects had two trials of picture-noise presentation-one with a picture of a spider and one with a picture of a flower-, either under an effective masking procedure (30 ms duration) or a non-effective masking procedure (500 ms duration). Order of presentation was counterbalanced. Dependent variables were heart rate and subjective assessment of the noise. Results showed an increased cardiac response in the first trial and a less reduced cardiac response in the second trial when the noise was preceded by the phobic picture under both masking procedures. The response was accompanied by an increase in the subjective unpleasantness of the noise. These results provide support to Ohman's theoretical model.

  14. Offshore Wind Turbines - Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine: Environmental Effects of Offshore Wind Energy Development

    SciTech Connect

    Aker, Pamela M.; Jones, Anthony M.; Copping, Andrea E.

    2010-11-23

    Deep C Wind, a consortium headed by the University of Maine will test the first U.S. offshore wind platforms in 2012. In advance of final siting and permitting of the test turbines off Monhegan Island, residents of the island off Maine require reassurance that the noise levels from the test turbines will not disturb them. Pacific Northwest National Laboratory, at the request of the University of Maine, and with the support of the U.S. Department of Energy Wind Program, modeled the acoustic output of the planned test turbines.

  15. The Marine Mask of War

    DTIC Science & Technology

    2011-11-10

    America’s Army. To the Marines, it is teamwork and the subordination of the individual to the common good of the unit. First person pronouns are shunned...As demonstrated over the last decade, this versatility and cost effectiveness is a good deal for the American taxpayer. Having examined the Mask

  16. Imaging With the IBIS Mask

    NASA Astrophysics Data System (ADS)

    Berná, J. A.; Torrejón, J. M.; Bernabeu, G.

    2001-03-01

    We present very preliminary results on the imaging capabilities of the IBIS instrument, the gamma ray imager on board ESA's INTEGRAL satellite, regarding the coded mask subsystem. For this purpose we perform a simulation of a pointed observation to the Galactic Centre region and investigate the detection of the most prominent sources.

  17. Masked Hypertension in Diabetes Mellitus

    PubMed Central

    Franklin, Stanley S.; Thijs, Lutgarde; Li, Yan; Hansen, Tine W.; Boggia, José; Liu, Yanping; Asayama, Kei; Björklund-Bodegård, Kristina; Ohkubo, Takayoshi; Jeppesen, Jørgen; Torp-Pedersen, Christian; Dolan, Eamon; Kuznetsova, Tatiana; Stolarz-Skrzypek, Katarzyna; Tikhonoff, Valérie; Malyutina, Sofia; Casiglia, Edoardo; Nikitin, Yuri; Lind, Lars; Sandoya, Edgardo; Kawecka-Jaszcz, Kalina; Filipovský, Jan; Imai, Yutaka; Wang, Jiguang; Ibsen, Hans; O’Brien, Eoin; Staessen, Jan A.

    2013-01-01

    Although distinguishing features of masked hypertension in diabetics are well known, the significance of antihypertensive treatment on clinical practice decisions has not been fully explored. We analyzed 9691 subjects from the population-based 11-country International Database on Ambulatory Blood Pressure in Relation to Cardiovascular Outcomes. Prevalence of masked hypertension in untreated normotensive participants was higher (P<0.0001) among 229 diabetics (29.3%, n=67) than among 5486 nondiabetics (18.8%, n=1031). Over a median of 11.0 years of follow-up, the adjusted risk for a composite cardiovascular end point in untreated diabetic-masked hypertensives tended to be higher than in normotensives (hazard rate [HR], 1.96; 95% confidence interval [CI], 0.97–3.97; P=0.059), similar to untreated stage 1 hypertensives (HR, 1.07; CI, 0.58–1.98; P=0.82), but less than stage 2 hypertensives (HR, 0.53; CI, 0.29–0.99; P=0.048). In contrast, cardiovascular risk was not significantly different in antihypertensive-treated diabetic-masked hypertensives, as compared with the normotensive comparator group (HR, 1.13; CI, 0.54–2.35; P=0.75), stage 1 hypertensives (HR, 0.91; CI, 0.49–1.69; P=0.76), and stage 2 hypertensives (HR, 0.65; CI, 0.35–1.20; P=0.17). In the untreated diabetic-masked hypertensive population, mean conventional systolic/diastolic blood pressure was 129.2±8.0/76.0±7.3 mm Hg, and mean daytime systolic/diastolic blood pressure 141.5±9.1/83.7±6.5 mm Hg. In conclusion, masked hypertension occurred in 29% of untreated diabetics, had comparable cardiovascular risk as stage 1 hypertension, and would require considerable reduction in conventional blood pressure to reach daytime ambulatory treatment goal. Importantly, many hypertensive diabetics when receiving antihypertensive therapy can present with normalized conventional and elevated ambulatory blood pressure that mimics masked hypertension. PMID:23478096

  18. "The Mask Who Wasn't There": Visual Masking Effect with the Perceptual Absence of the Mask

    ERIC Educational Resources Information Center

    Rey, Amandine Eve; Riou, Benoit; Muller, Dominique; Dabic, Stéphanie; Versace, Rémy

    2015-01-01

    Does a visual mask need to be perceptually present to disrupt processing? In the present research, we proposed to explore the link between perceptual and memory mechanisms by demonstrating that a typical sensory phenomenon (visual masking) can be replicated at a memory level. Experiment 1 highlighted an interference effect of a visual mask on the…

  19. How anthropogenic noise affects foraging.

    PubMed

    Luo, Jinhong; Siemers, Björn M; Koselj, Klemen

    2015-09-01

    The influence of human activity on the biosphere is increasing. While direct damage (e.g. habitat destruction) is relatively well understood, many activities affect wildlife in less apparent ways. Here, we investigate how anthropogenic noise impairs foraging, which has direct consequences for animal survival and reproductive success. Noise can disturb foraging via several mechanisms that may operate simultaneously, and thus, their effects could not be disentangled hitherto. We developed a diagnostic framework that can be applied to identify the potential mechanisms of disturbance in any species capable of detecting the noise. We tested this framework using Daubenton's bats, which find prey by echolocation. We found that traffic noise reduced foraging efficiency in most bats. Unexpectedly, this effect was present even if the playback noise did not overlap in frequency with the prey echoes. Neither overlapping noise nor nonoverlapping noise influenced the search effort required for a successful prey capture. Hence, noise did not mask prey echoes or reduce the attention of bats. Instead, noise acted as an aversive stimulus that caused avoidance response, thereby reducing foraging efficiency. We conclude that conservation policies may seriously underestimate numbers of species affected and the multilevel effects on animal fitness, if the mechanisms of disturbance are not considered.

  20. A synthesis of two decades of research documenting the effects of noise on wildlife.

    PubMed

    Shannon, Graeme; McKenna, Megan F; Angeloni, Lisa M; Crooks, Kevin R; Fristrup, Kurt M; Brown, Emma; Warner, Katy A; Nelson, Misty D; White, Cecilia; Briggs, Jessica; McFarland, Scott; Wittemyer, George

    2016-11-01

    Global increases in environmental noise levels - arising from expansion of human populations, transportation networks, and resource extraction - have catalysed a recent surge of research into the effects of noise on wildlife. Synthesising a coherent understanding of the biological consequences of noise from this literature is challenging. Taxonomic groups vary in auditory capabilities. A wide range of noise sources and exposure levels occur, and many kinds of biological responses have been observed, ranging from individual behaviours to changes in ecological communities. Also, noise is one of several environmental effects generated by human activities, so researchers must contend with potentially confounding explanations for biological responses. Nonetheless, it is clear that noise presents diverse threats to species and ecosystems and salient patterns are emerging to help inform future natural resource-management decisions. We conducted a systematic and standardised review of the scientific literature published from 1990 to 2013 on the effects of anthropogenic noise on wildlife, including both terrestrial and aquatic studies. Research to date has concentrated predominantly on European and North American species that rely on vocal communication, with approximately two-thirds of the data set focussing on songbirds and marine mammals. The majority of studies documented effects from noise, including altered vocal behaviour to mitigate masking, reduced abundance in noisy habitats, changes in vigilance and foraging behaviour, and impacts on individual fitness and the structure of ecological communities. This literature survey shows that terrestrial wildlife responses begin at noise levels of approximately 40 dBA, and 20% of papers documented impacts below 50 dBA. Our analysis highlights the utility of existing scientific information concerning the effects of anthropogenic noise on wildlife for predicting potential outcomes of noise exposure and implementing

  1. Noise Mapping and Annoyance.

    PubMed

    Knauss, D.

    2002-01-01

    The EC has published a Green Paper on noise policy in the EU and has issued a directive on the assessment and reduction of environmental noise. This directive will make noise mapping mandatory for cities with at least 250.000 inhabitants. Due to the development in computer technology it is possible to calculate noise maps for large urban areas using the available data on buildings, ground profile, road and rail traffic. Examples for noise mapping are Birmingham (GB), Linz (A) and various German cities. Based on noise maps and empirical data on the correlation between annoyance and noise levels annoyance maps for different sources (rail, road, aircraft) can be calculated. Under the assumption that the annoyance for the different sources are only weakly correlated, a combined annoyance map can be calculated. In a second step using the distribution of the population the actual number of annoyed people can be evaluated. This analysis can be used, for example, to identify noise hot spots and to assess the impact of major traffic projects - roads, airports- on the noise situation as well as the impact on the population. Furthermore, the combined annoyance maps can be used to investigate on health effects and to check whether or not empirical correlations between annoyance and noise levels are sufficiently correct.

  2. Method for mask repair using defect compensation

    DOEpatents

    Sweeney, Donald W.; Ray-Chaudhuri, Avijit K.

    2001-01-01

    A method for repair of amplitude and/or phase defects in lithographic masks. The method involves modifying or altering a portion of the absorber pattern on the surface of the mask blank proximate to the mask defect to compensate for the local disturbance (amplitude or phase) of the optical field due to the defect.

  3. 21 CFR 868.5600 - Venturi mask.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Venturi mask. 868.5600 Section 868.5600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5600 Venturi mask. (a) Identification. A venturi mask is...

  4. 47 CFR 90.210 - Emission masks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Emission masks. 90.210 Section 90.210... MOBILE RADIO SERVICES General Technical Standards § 90.210 Emission masks. Except as indicated elsewhere... emission masks outlined in this section. Unless otherwise stated, per paragraphs (d)(4), (e)(4), and (m)...

  5. 47 CFR 90.210 - Emission masks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Emission masks. 90.210 Section 90.210... MOBILE RADIO SERVICES General Technical Standards § 90.210 Emission masks. Except as indicated elsewhere... emission masks outlined in this section. Unless otherwise stated, per paragraphs (d)(4), (e)(4), and (o)...

  6. 47 CFR 90.210 - Emission masks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Emission masks. 90.210 Section 90.210... MOBILE RADIO SERVICES General Technical Standards § 90.210 Emission masks. Except as indicated elsewhere... emission masks outlined in this section. Unless otherwise stated, per paragraphs (d)(4), (e)(4), and (o)...

  7. 47 CFR 90.210 - Emission masks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission masks. 90.210 Section 90.210... MOBILE RADIO SERVICES General Technical Standards § 90.210 Emission masks. Except as indicated elsewhere... emission masks outlined in this section. Unless otherwise stated, per paragraphs (d)(4), (e)(4), and (m)...

  8. 47 CFR 90.210 - Emission masks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Emission masks. 90.210 Section 90.210... MOBILE RADIO SERVICES General Technical Standards § 90.210 Emission masks. Except as indicated elsewhere... emission masks outlined in this section. Unless otherwise stated, per paragraphs (d)(4), (e)(4), and (m)...

  9. 21 CFR 868.5580 - Oxygen mask.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Oxygen mask. 868.5580 Section 868.5580 Food and... ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5580 Oxygen mask. (a) Identification. An oxygen mask is a device placed over a patient's nose, mouth, or tracheostomy to administer oxygen or aerosols. (b)...

  10. 21 CFR 868.5580 - Oxygen mask.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Oxygen mask. 868.5580 Section 868.5580 Food and... ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5580 Oxygen mask. (a) Identification. An oxygen mask is a device placed over a patient's nose, mouth, or tracheostomy to administer oxygen or aerosols. (b)...

  11. 21 CFR 868.5580 - Oxygen mask.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oxygen mask. 868.5580 Section 868.5580 Food and... ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5580 Oxygen mask. (a) Identification. An oxygen mask is a device placed over a patient's nose, mouth, or tracheostomy to administer oxygen or aerosols. (b)...

  12. 21 CFR 868.5580 - Oxygen mask.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Oxygen mask. 868.5580 Section 868.5580 Food and... ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5580 Oxygen mask. (a) Identification. An oxygen mask is a device placed over a patient's nose, mouth, or tracheostomy to administer oxygen or aerosols. (b)...

  13. 21 CFR 868.5580 - Oxygen mask.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Oxygen mask. 868.5580 Section 868.5580 Food and... ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5580 Oxygen mask. (a) Identification. An oxygen mask is a device placed over a patient's nose, mouth, or tracheostomy to administer oxygen or aerosols. (b)...

  14. Advanced Jet Noise Exhaust Concepts in NASA's N+2 Supersonics Validation Study and the Environmentally Responsible Aviation Project's Upcoming Hybrid Wing Body Acoustics Test

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda S.; Doty, Mike

    2012-01-01

    Acoustic and flow-field experiments were conducted on exhaust concepts for the next generation supersonic, commercial aircraft. The concepts were developed by Lockheed Martin (LM), Rolls-Royce Liberty Works (RRLW), and General Electric Global Research (GEGR) as part of an N+2 (next generation forward) aircraft system study initiated by the Supersonics Project in NASA s Fundamental Aeronautics Program. The experiments were conducted in the Aero-Acoustic Propulsion Laboratory at the NASA Glenn Research Center. The exhaust concepts presented here utilized lobed-mixers and ejectors. A powered third-stream was implemented to improve ejector acoustic performance. One concept was found to produce stagnant flow within the ejector and the other produced discrete-frequency tones (due to flow separations within the model) that degraded the acoustic performance of the exhaust concept. NASA's Environmentally Responsible Aviation (ERA) Project has been investigating a Hybrid Wing Body (HWB) aircraft as a possible configuration for meeting N+2 system level goals for noise, emissions, and fuel burn. A recently completed NRA led by Boeing Research and Technology resulted in a full-scale aircraft design and wind tunnel model. This model will be tested acoustically in NASA Langley's 14-by 22-Foot Subsonic Tunnel and will include dual jet engine simulators and broadband engine noise simulators as part of the test campaign. The objectives of the test are to characterize the system level noise, quantify the effects of shielding, and generate a valuable database for prediction method development. Further details of the test and various component preparations are described.

  15. Object Substitution Masking Induced by Illusory Masks: Evidence for Higher Object-Level Locus of Interference

    ERIC Educational Resources Information Center

    Hirose, Nobuyuki; Osaka, Naoyuki

    2009-01-01

    A briefly presented target can be rendered invisible by a lingering sparse mask that does not even touch it. This form of visual backward masking, called object substitution masking, is thought to occur at the object level of processing. However, it remains unclear whether object-level interference alone produces substitution masking because…

  16. Relations between environmental noise and electronic coupling for optimal exciton transfer in one- and two-dimensional homogeneous and inhomogeneous quantum systems

    SciTech Connect

    Forgy, Charles C.; Mazziotti, David A.

    2014-12-14

    Recent studies have indicated that environmental noise may increase energy-transfer efficiency in quantum systems. For homogeneous networks of chromophores previous studies have primarily considered excitonic transport in one-dimensional (linear) networks. In our study, we expand previous research to a two-dimensional fully coupled topology of chromophore molecules. We demonstrate that not only does an optimal dephasing rate exist in both one- and two-dimensional networks but also that it increases in magnitude with increasing coupling strength between chromophores. Optimal transport occurs when the noise quenches the entanglement between local modes that prevent the exciton from moving efficiently to the target site. We find that these results are insensitive to minor site defects such as those found in realistic systems. We contrast these findings to systems with a high degree of inhomogeneity, in which the optimal dephasing rate is largely set by the system topology and does not vary significantly with respect to coupling strength. Our findings have potential applications to systems such as quantum dot arrays and carbon nanotube structures.

  17. Performance of GFIS mask repair system for various mask materials

    NASA Astrophysics Data System (ADS)

    Aramaki, Fumio; Kozakai, Tomokazu; Matsuda, Osamu; Yasaka, Anto; Yoshikawa, Shingo; Kanno, Koichi; Miyashita, Hiroyuki; Hayashi, Naoya

    2014-10-01

    We have developed a new focused ion beam (FIB) technology using a gas field ion source (GFIS) for mask repair. Meanwhile, since current high-end photomasks do not have high durability in exposure nor cleaning, some new photomask materials are proposed. In 2012, we reported that our GFIS system had repaired a representative new material "A6L2". It is currently expected to extend the application range of GFIS technology for various new materials and various defect shapes. In this study, we repaired a single bridge, a triple bridge and a missing hole on a phase shift mask (PSM) of "A6L2", and also repaired single bridges on a binary mask of molybdenum silicide (MoSi) material "W4G" and a PSM of high transmittance material "SDC1". The etching selectivity between those new materials and quartz were over 4:1. There were no significant differences of pattern shapes on scanning electron microscopy (SEM) images between repair and non-repair regions. All the critical dimensions (CD) at repair regions were less than +/-3% of those at normal ones on an aerial image metrology system (AIMS). Those results demonstrated that GFIS technology is a reliable solution of repairing new material photomasks that are candidates for 1X nm generation.

  18. 77 FR 18297 - Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation Environmental Design Tool...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ...-5047. SUPPLEMENTARY INFORMATION: Background: FAA Order 1050.1E, Environmental Impacts: Policies and... (NEPA). Under FAA Order 1050.1E, Appendix A, Section 2.4c, states ``the EDMS is FAA's required... Order 1050.1E, Appendix A, Section 13.2a describes the FAA policy to conserve resources such as...

  19. The effect of spatial separation on informational and energetic masking of speech.

    PubMed

    Arbogast, Tanya L; Mason, Christine R; Kidd, Gerald

    2002-11-01

    The effect of spatial separation of sources on the masking of a speech signal was investigated for three types of maskers, ranging from energetic to informational. Normal-hearing listeners performed a closed-set speech identification task in the presence of a masker at various signal-to-noise ratios. Stimuli were presented in a quiet sound field. The signal was played from 0 degrees azimuth and a masker was played either from the same location or from 90 degrees to the right. Signals and maskers were derived from sentences that were preprocessed by a modified cochlear-implant simulation program that filtered each sentence into 15 frequency bands, extracted the envelopes from each band, and used these envelopes to modulate pure tones at the center frequencies of the bands. In each trial, the signal was generated by summing together eight randomly selected frequency bands from the preprocessed signal sentence. Three maskers were derived from the preprocessed masker sentences: (1) different-band sentence, which was generated by summing together six randomly selected frequency bands out of the seven bands not present in the signal (resulting in primarily informational masking); (2) different-band noise, which was generated by convolving the different-band sentence with Gaussian noise; and (3) same-band noise, which was generated by summing the same eight bands from the preprocessed masker sentence that were used in the signal sentence and convolving the result with Gaussian noise (resulting in primarily energetic masking). Results revealed that in the different-band sentence masker, the effect of spatial separation averaged 18 dB (at 51% correct), while in the different-band and same-band noise maskers the effect was less than 10 dB. These results suggest that, in these conditions, the advantage due to spatial separation of sources is greater for informational masking than for energetic masking.

  20. Image discrimination models predict detection in fixed but not random noise

    NASA Technical Reports Server (NTRS)

    Ahumada, A. J. Jr; Beard, B. L.; Watson, A. B. (Principal Investigator)

    1997-01-01

    By means of a two-interval forced-choice procedure, contrast detection thresholds for an aircraft positioned on a simulated airport runway scene were measured with fixed and random white-noise masks. The term fixed noise refers to a constant, or unchanging, noise pattern for each stimulus presentation. The random noise was either the same or different in the two intervals. Contrary to simple image discrimination model predictions, the same random noise condition produced greater masking than the fixed noise. This suggests that observers seem unable to hold a new noisy image for comparison. Also, performance appeared limited by internal process variability rather than by external noise variability, since similar masking was obtained for both random noise types.

  1. Airport noise

    NASA Technical Reports Server (NTRS)

    Pendley, R. E.

    1982-01-01

    The problem of airport noise at several airports and air bases is detailed. Community reactions to the noise, steps taken to reduce jet engine noise, and the effect of airport use restrictions and curfews on air transportation are discussed. The adverse effect of changes in allowable operational noise on airport safety and altenative means for reducing noise pollution are considered. Community-airport relations and public relations are discussed.

  2. Combustion noise

    NASA Technical Reports Server (NTRS)

    Strahle, W. C.

    1977-01-01

    A review of the subject of combustion generated noise is presented. Combustion noise is an important noise source in industrial furnaces and process heaters, turbopropulsion and gas turbine systems, flaring operations, Diesel engines, and rocket engines. The state-of-the-art in combustion noise importance, understanding, prediction and scaling is presented for these systems. The fundamentals and available theories of combustion noise are given. Controversies in the field are discussed and recommendations for future research are made.

  3. Velocity and structural model of the Lower Tagus Basin according to the study of environmental seismic noise

    NASA Astrophysics Data System (ADS)

    Gomes Torres, Ricardo Jorge; Furtado, José Augusto; Gonçalves Silva, Hugo; Borges, José Fernando; Caldeira, Bento; Bezzeghoud, Mourad; Carvalho, João

    2013-04-01

    Along his history the Lower Tagus Valley (LTV) region was shaken by several earthquakes, some of them produced in large ruptures of offshore structures located southwest of the Portuguese coastline. Among these is the Lisbon earthquake of 1 November 1755 (M~8.5-8.7), and other moderates earthquakes that were produced by local sources such as the 1344 (M6.0), 1531 (M7.1) and 1909 (M6.0) earthquakes. Previous simulations [1] have shown high velocity amplification in the region. The model used in the simulations was updated from low to high resolution using all the new available geophysical and geotechnical data on the area (seismic reflection, aeromagnetic, gravimetric, deep wells and geological outcrops) [2]. To confirm this model in the areas where it was derived by potential field methods we use broadband ambient noise measurements collected in about 200 points along seven profiles on the LTV basin, six perpendicular and one parallel to the basin axis. We applied the horizontal to vertical (H/V) spectral ratio method [3] to the seismic noise profiles in order to estimate the distribution of amplification in the basin. The H/V curves obtained reveals the existence of two low frequency peaks centered on 0.2 and 1 Hz [4]. These peaks are strongly related with the thickness of Cenozoic and alluvial sediments. The velocity model obtained by inversion of the H/V curves is in good agreement with borehole data, and results obtained using seismic reflection and gravimetric methods. However, aeromagnetic data overestimates the depth of the base of Cenozoic in the areas where it overlies directly the paleozoic basement, which we attribute either to the existence of Mesozoic units or higher magnetic susceptibilities than expected for the Paleozoic. References: [1] Bezzeghoud, M., Borges, J.F., M., Caldeira (2011). Ground motion simulations of the SW Iberia margin: rupture directivity and earth structure effects. Natural Hazards, pages 1-17. doi:10.1007/s11069-011-9925-2 [2

  4. Improving vision by pupil masking

    PubMed Central

    Bonaque-González, Sergio; Ríos-Rodríguez, Susana; López-Gil, Norberto

    2016-01-01

    We propose an alternative solution to improve visual quality by spatially modulating the amplitude of light passing into the eye (related to the eye's transmittance), in contrast to traditional correction of the wavefront phase (related to the local refractive power). Numerical simulations show that masking the aberrated areas at the pupil plane should enhance visual function, especially in highly aberrated eyes. This correction could be implemented in practice using customized contact or intraocular lenses. PMID:27446688

  5. Mask pattern generator employing EPL technology

    NASA Astrophysics Data System (ADS)

    Yoshioka, Nobuyuki; Yamabe, Masaki; Wakamiya, Wataru; Endo, Nobuhiro

    2003-08-01

    Mask cost is one of crucial issues in device fabrication, especially in SoC (System on a Chip) with small-volume production. The cost mainly depends on productivity of mask manufacturing tools such as mask writers and defect inspection tools. EPL (Electron Projection Lithography) has been developing as a high-throughput electron beam exposure technology that will succeed optical lithography. The application of EPL technology to mask writing will result in high productivity and contribute to decrease the mask cost. The concept of a mask pattern generator employing EPL technology is proposed in this paper. It is very similar to EPL technology used for pattern printing on a wafer. The mask patterns on the glass substrate are exposed by projecting the basic circuit patterns formed on the mother EPL mask. One example of the mother EPL mask is a stencil type made with 200-mm Si wafer. The basic circuit patterns are IP patterns and logical primitive patterns such as cell libraries (AND, OR, Inverter, Flip-Flop and etc.) to express the SoC device patterns. Since the SoC patterns are exposed with its collective units such as IP and logical primitive patterns by using this method, the high throughput will be expected comparing with conventional mask E-beam writers. In this paper, the mask pattern generator with the EPL technology is proposed. The concept, its advantages and issues to be solved are discussed.

  6. Image Denoising With Edge-Preserving and Segmentation Based on Mask NHA.

    PubMed

    Hosotani, Fumitaka; Inuzuka, Yuya; Hasegawa, Masaya; Hirobayashi, Shigeki; Misawa, Tadanobu

    2015-12-01

    In this paper, we propose a zero-mean white Gaussian noise removal method using a high-resolution frequency analysis. It is difficult to separate an original image component from a noise component when using discrete Fourier transform or discrete cosine transform for analysis because sidelobes occur in the results. The 2D non-harmonic analysis (2D NHA) is a high-resolution frequency analysis technique that improves noise removal accuracy because of its sidelobe reduction feature. However, spectra generated by NHA are distorted, because of which the signal of the image is non-stationary. In this paper, we analyze each region with a homogeneous texture in the noisy image. Non-uniform regions that occur due to segmentation are analyzed by an extended 2D NHA method called Mask NHA. We conducted an experiment using a simulation image, and found that Mask NHA denoising attains a higher peak signal-to-noise ratio (PSNR) value than the state-of-the-art methods if a suitable segmentation result can be obtained from the input image, even though parameter optimization was incomplete. This experimental result exhibits the upper limit on the value of PSNR in our Mask NHA denoising method. The performance of Mask NHA denoising is expected to approach the limit of PSNR by improving the segmentation method.

  7. Development of Spatial Release from Masking in Mandarin-Speaking Children with Normal Hearing

    ERIC Educational Resources Information Center

    Yuen, Kevin C. P.; Yuan, Meng

    2014-01-01

    Purpose: This study investigated the development of spatial release from masking in children using closed-set Mandarin disyllabic words and monosyllabic words carrying lexical tones as test stimuli and speech spectrum-weighted noise as a masker. Method: Twenty-six children ages 4-9 years and 12 adults, all with normal hearing, participated in…

  8. Spatial release from informational masking

    NASA Astrophysics Data System (ADS)

    Rakerd, Brad; Aaronson, Neil L.

    2001-05-01

    A new method for investigating spatial release from informational masking was developed and employed in two experiments. The new method is computer controlled and efficient. It employs the versatile coordinate response measure speech stimulus set [Bolia et al., J. Acoust. Soc. Am. 107, 1065 (2000)]. The experiments were conducted in an anechoic room, with a primary loudspeaker in front of the listener and a secondary loudspeaker at 60 deg to the right. Target messages were presented from the primary speaker only. For a standard, distractor messages, simultaneous with the target, were also presented from the primary speaker only. Spatial release was measured by presenting the distractors from both primary and secondary speakers with a temporal offset. Experiment 1 fixed the offset (secondary leading, +4 ms) and varied the number of distractors (1 to 3) and the target-to-distractor ratio (-12 to +4 dB). Masking release, sometimes as large as 10 dB, was found for all combinations of these variables. Experiment 2 varied the offset over a wide range of values. Substantial release from masking was found for both positive and negative offsets, but only in the range in which speech echoes are suppressed (<50 ms). [Work supported by NIDCD grant DC 00181.

  9. History and future of mask making

    NASA Astrophysics Data System (ADS)

    Levy, Ken L.

    1996-12-01

    The history of the mask industry has three main periods, which I call the Classical Period, the Dark Ages, and the Renaissance, by analogy with those periods in the history of Western Europe. During the Classical Period, people developed 1X masks and the technology to make them. In the Dark Ages, people exploited the equipment developed during the Classical Period to make 5X reduction reticle, ending the nobility of mask making. In today's Renaissance of mask making, a proliferation of mask types is requiring a rebirth of innovation and creativity. The Renaissance resembles the Classical Period: masks are once again strategic, and technological capability is once again the driver. Meanwhile, the mask industry is carrying forward the productivity and efficiency gains it achieved during the Dark Ages. We must create a new business and economic model to support these changes in the characteristics of the marketplace.

  10. Synchronized chaotic phase masks for encrypting and decrypting images

    NASA Astrophysics Data System (ADS)

    Rueda, Edgar; Vera, Carlos A.; Rodríguez, Boris; Torroba, Roberto

    2008-12-01

    This paper presents an alternative to secure exchange of encrypted information through public open channels. Chaotic encryption introduces a security improvement by an efficient masking of the message with a chaotic signal. Message extraction by an authorized end user is done using a synchronization procedure, thus allowing a continuous change of the encrypting and decrypting keys. And optical implementation with a 4f optical encrypting architecture is suggested. Digital simulations, including the effects of missing data, corrupted data and noise addition are shown. These results proof the consistency of the proposal, and demonstrate a practical way to operate with it.

  11. Spatial Hearing, Attention and Informational Masking in Speech Identification

    DTIC Science & Technology

    2012-09-12

    Best, V., Gallun, F.J., Mason, C.R., Kidd, G. Jr. and Shinn-Cunningham, B.G. (2009) “The impact of noise and hearing loss on the processing of... rooms " J. Acoust. Soc. Am., 24, 3064-3075 uating the benefit of hearing aids in olving the cocktail party problem," Trends in Amplification, 12, 300...E7(/(3+21(180%(5 ,QFOXGHDUHDFRGH 12 Spe 2012 Final Technical 1 Aug 2008 - 30 Nov 2011 Spatial hearing , attention and informational masking

  12. Fabrication and commercialization of scalpel masks

    NASA Astrophysics Data System (ADS)

    Novembre, Anthony E.; Peabody, Milton L., Jr.; Blakey, Myrtle I.; Farrow, Reginald C.; Kasica, Richard J.; Liddle, James A.; Saunders, Thomas E.; Tennant, Donald M.

    1998-09-01

    SCALPEL masks have been fabricated for use in the Proof-of- Lithography system and to demonstrate the feasibility of having them produced by a commercial blank manufacturer and optical mask shops. Masks blanks are formed from 100 mm diameter silicon wafers. A 100-150 nm thick SiNx layer is LPCVD deposited onto the wafers followed by magnetron sputter deposition of a thin Cr/W metal layer which is used as the scatterer layer for the mask>the mask is supported by an underlying network of struts which are arranged to be compatible with the step and scan writing strategy of the exposure tool and to provide robustness to the mask. Crystallographic wet etching of the silicon wafer forms membranes and struts. To date over 300 mask blanks have been formed and yield data as a function of the thickness of the silicon nitride membrane has been quantified. Recent developments in the mask blank formation process include the production of blanks by MCNC who serve as a commercial source of SCALPEL mask blanks. They have successfully delivered 36 blanks that exhibit equivalent properties to those produced at Lucent. Mask patterning has been performed at the commercial optical mask shops of PHOTRONICS and DUPONT. In this investigation a MEBES exposure system has been used to write patterns. The resist used is ZEP-520 and development and pattern transfer processes are performed in the STEAG-Hammatech spray/spin processing tool. Metrology is performed using a KMS 310 RT optical microscope. Pattern placement accuracy is measured on the LMS 2020 system without modification. The masks are inspected for defects using the optical based KLA 300 series inspection system in a die to die mode and in transmission. Results to date suggest feasibility of producing SCALPEL masks by a commercial blank supplier and by merchant optical mask shops.

  13. Noise and Attentional Selectivity: A Reproducible Phenomenon?

    ERIC Educational Resources Information Center

    Forster, Peter M.; Grierson, Arthur T.

    1978-01-01

    Four pursuit-tracking experiments were conducted in an attempt to replicate with adults, Hockey's findings that loud noise increases attentional selectivity. Neither attentional selectivity nor masking of auditory feedback was found to be significant. For Hockey's reply and the authors' rejoinder, see p499-506 of this issue. (SJL)

  14. Self-Report of Transportation Noise Exposure, Annoyance and Noise Sensitivity in Relation to Noise Map Information

    NASA Astrophysics Data System (ADS)

    HEINONEN-GUZEJEV, M.; VUORINEN, H. S.; KAPRIO, J.; HEIKKILÄ, K.; MUSSALO-RAUHAMAA, H.; KOSKENVUO, M.

    2000-07-01

    Self-report of noise exposure was compared with the information on noise maps while taking into account measures of self-reported annoyance and noise sensitivity. Self-report data were analyzed for 1495 subjects participating in a case-control study of hypertension from the Finnish Twin Cohort who had replied to a questionnaire in 1988. In addition, noise map information was included in analyses of the 218 study subjects living in the Metropolitan Area of Helsinki. The results show that: (1) In the factor analysis based on all subjects self-report of transportation noise exposure formed an own factor independent of the annoyance variables or noise sensitivity. Annoyance items loaded on to two different factors termed nighttime and daytime annoyance. Noise sensitivity did not load to either of the factors of annoyance. For the subsample with noise map information, the results indicated that: (2) Noise sensitivity was independent of noise map information. (3) Subjects with high noise sensitivity reported more transportation noise exposure than subjects with low noise sensitivity and they reported aircraft, railway and road traffic noise exposure outside the environmental noise map areas almost twice as often as non-sensitive subjects. (4) Noise map information and self-report of noise exposure were consistently associated when aircraft noise was considered. Self-report of noise related items may supplement noise map information in noise protection.

  15. Intelligibility of whispered speech in stationary and modulated noise maskers

    PubMed Central

    Freyman, Richard L.; Griffin, Amanda M.; Oxenham, Andrew J.

    2012-01-01

    This study investigated the role of natural periodic temporal fine structure in helping listeners take advantage of temporal valleys in amplitude-modulated masking noise when listening to speech. Young normal-hearing participants listened to natural, whispered, and/or vocoded nonsense sentences in a variety of masking conditions. Whispering alters normal waveform temporal fine structure dramatically but, unlike vocoding, does not degrade spectral details created by vocal tract resonances. The improvement in intelligibility, or masking release, due to introducing 16-Hz square-wave amplitude modulations in an otherwise steady speech-spectrum noise was reduced substantially with vocoded sentences relative to natural speech, but was not reduced for whispered sentences. In contrast to natural speech, masking release for whispered sentences was observed even at positive signal-to-noise ratios. Whispered speech has a different short-term amplitude distribution relative to natural speech, and this appeared to explain the robust masking release for whispered speech at high signal-to-noise ratios. Recognition of whispered speech was not disproportionately affected by unpredictable modulations created by a speech-envelope modulated noise masker. Overall, the presence or absence of periodic temporal fine structure did not have a major influence on the degree of benefit obtained from imposing temporal fluctuations on a noise masker. PMID:23039445

  16. Signal-to-Noise Ratio in Physical Education Settings

    ERIC Educational Resources Information Center

    Ryan, Stu; Grube, Dan; Mokgwathi, Martin M.

    2010-01-01

    It is generally known that in educational settings, excessive noise masks what the teacher is saying; thus, and for maximum learning to occur, the teacher's voice must be highly intelligible to all children (Crandell, Smaldino, & Flexer, 1995). The difference between what the teacher is saying (signal) and the classroom noise level is commonly…

  17. Effects of Tidal Turbine Noise on Fish Task 2.1.3.2: Effects on Aquatic Organisms: Acoustics/Noise - Fiscal Year 2011 - Progress Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30

    Naturally spawning stocks of Chinook salmon (Oncorhynchus tshawytscha) that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/ Chinook/CKPUG.cfm). Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study (Effects on Aquatic Organisms, Subtask 2.1.3.2: Acoustics) was performed during FY 2011 to determine if noise generated by a 6-m-diameter open-hydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Preliminary results indicate that low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

  18. High performance mask fabrication process for the next-generation mask production

    NASA Astrophysics Data System (ADS)

    Yagawa, Keisuke; Ugajin, Kunihiro; Suenaga, Machiko; Kobayashi, Yoshihito; Motokawa, Takeharu; Hagihara, Kazuki; Saito, Masato; Itoh, Masamitsu

    2014-07-01

    ArF immersion lithography combined with double patterning has been used for fabricating below half pitch 40nm devices. However, when pattern size shrinks below 20nm, we must use new technology like quadruple patterning process or next generation lithography (NGL) solutions. Moreover, with change in lithography tool, next generation mask production will be needed. According to ITRS 2013, fabrication of finer patterns less than 15nm will be required on mask plate in NGL mask production 5 years later [1]. In order to fabricate finer patterns on mask, higher resolution EB mask writer and high performance fabrication process will be required. In a previous study, we investigated a potential of mask fabrication process for finer patterning and achieved 17nm dense line pattern on mask plate by using VSB (Variable Shaped Beam) type EB mask writer and chemically amplified resist [2][3]. After a further investigation, we constructed higher performance mask process by using new EB mask writer EBM9000. EBM9000 is the equipment supporting hp16nm generation's photomask production and has high accuracy and high throughput. As a result, we achieved 15.5nm pattern on mask with high productivity. Moreover, from evaluation of isolated pattern, we proved that current mask process has the capability for sub-10nm pattern. These results show that the performance of current mask fabrication process have the potential to fabricate the next-generation mask.

  19. Traffic noise reduces foraging efficiency in wild owls

    NASA Astrophysics Data System (ADS)

    Senzaki, Masayuki; Yamaura, Yuichi; Francis, Clinton D.; Nakamura, Futoshi

    2016-08-01

    Anthropogenic noise has been increasing globally. Laboratory experiments suggest that noise disrupts foraging behavior across a range of species, but to reveal the full impacts of noise, we must examine the impacts of noise on foraging behavior among species in the wild. Owls are widespread nocturnal top predators and use prey rustling sounds for localizing prey when hunting. We conducted field experiments to examine the effect of traffic noise on owls’ ability to detect prey. Results suggest that foraging efficiency declines with increasing traffic noise levels due to acoustic masking and/or distraction and aversion to traffic noise. Moreover, we estimate that effects of traffic noise on owls’ ability to detect prey reach >120 m from a road, which is larger than the distance estimated from captive studies with bats. Our study provides the first evidence that noise reduces foraging efficiency in wild animals, and highlights the possible pervasive impacts of noise.

  20. Traffic noise reduces foraging efficiency in wild owls

    PubMed Central

    Senzaki, Masayuki; Yamaura, Yuichi; Francis, Clinton D.; Nakamura, Futoshi

    2016-01-01

    Anthropogenic noise has been increasing globally. Laboratory experiments suggest that noise disrupts foraging behavior across a range of species, but to reveal the full impacts of noise, we must examine the impacts of noise on foraging behavior among species in the wild. Owls are widespread nocturnal top predators and use prey rustling sounds for localizing prey when hunting. We conducted field experiments to examine the effect of traffic noise on owls’ ability to detect prey. Results suggest that foraging efficiency declines with increasing traffic noise levels due to acoustic masking and/or distraction and aversion to traffic noise. Moreover, we estimate that effects of traffic noise on owls’ ability to detect prey reach >120 m from a road, which is larger than the distance estimated from captive studies with bats. Our study provides the first evidence that noise reduces foraging efficiency in wild animals, and highlights the possible pervasive impacts of noise. PMID:27537709

  1. Seismic arrival enhancement through the use of noise whitening

    NASA Astrophysics Data System (ADS)

    Birnie, Claire; Chambers, Kit; Angus, Doug

    2017-01-01

    A constant feature in seismic data, noise is particularly troublesome for passive seismic monitoring where noise commonly masks microseismic events. We propose a statistics-driven noise suppression technique that whitens the noise through the calculation and removal of the noise's covariance. Noise whitening is shown to reduce the noise energy by a factor of 3.5 resulting in microseismic events being observed and imaged at lower signal to noise ratios than originally possible - whilst having negligible effect on the seismic wavelet. The procedure is shown to be highly resistant to most changes in the noise properties and has the flexibility of being used as a stand-alone technique or as a first step before standard random noise attenuation methods.

  2. Maximum Likelihood Expectation-Maximization Algorithms Applied to Localization and Identification of Radioactive Sources with Recent Coded Mask Gamma Cameras

    SciTech Connect

    Lemaire, H.; Barat, E.; Carrel, F.; Dautremer, T.; Dubos, S.; Limousin, O.; Montagu, T.; Normand, S.; Schoepff, V.; Amgarou, K.; Menaa, N.; Angelique, J.-C.; Patoz, A.

    2015-07-01

    In this work, we tested Maximum likelihood expectation-maximization (MLEM) algorithms optimized for gamma imaging applications on two recent coded mask gamma cameras. We respectively took advantage of the characteristics of the GAMPIX and Caliste HD-based gamma cameras: noise reduction thanks to mask/anti-mask procedure but limited energy resolution for GAMPIX, high energy resolution for Caliste HD. One of our short-term perspectives is the test of MAPEM algorithms integrating specific prior values for the data to reconstruct adapted to the gamma imaging topic. (authors)

  3. Holographically Encoded Volume Phase Masks

    DTIC Science & Technology

    2015-07-13

    experiments have been performed using an HPM recorded in a 1.97-mm thick photo -thermo-refractive (PTR) glass sample as illustrated in Fig. 1. PTR glass is a...spiral phase plate,” Appl. Opt. 43(12), 2397–2399 (2004). 19. K. Peithmann et al., “Low-spatial-frequency refractive-index changes in iron- doped ...Binary volume phase masks in photo -thermo-refrac- tive glass,” Opt. Lett. 37(7), 1190–1192 (2012). 21. M. Bass, Handbook of Optics, 2nd ed., McGraw-Hill

  4. Procedures for dealing with certain types of noise and systematic errors common to many Hadamard transform optical systems

    NASA Technical Reports Server (NTRS)

    Harwit, M.

    1977-01-01

    Sources of noise and error correcting procedures characteristic of Hadamard transform optical systems were investigated. Reduction of spectral noise due to noise spikes in the data, the effect of random errors, the relative performance of Fourier and Hadamard transform spectrometers operated under identical detector-noise-limited conditions, and systematic means for dealing with mask defects are among the topics discussed. The distortion in Hadamard transform optical instruments caused by moving Masks, incorrect mask alignment, missing measurements, and diffraction is analyzed and techniques for reducing or eliminating this distortion are described.

  5. Community noise

    NASA Technical Reports Server (NTRS)

    Bragdon, C. R.

    1982-01-01

    Airport and community land use planning as they relate to airport noise reduction are discussed. Legislation, community relations, and the physiological effect of airport noise are considered. Noise at the Logan, Los Angeles, and Minneapolis/St. Paul airports is discussed.

  6. Aircraft noise, hearing ability, and annoyance

    SciTech Connect

    Wu, Trong-Neng; Jim Shoung Lai; Chen-Yang Shen

    1995-11-01

    The relationship between aircraft noise, loss of hearing, and annoyance was explored in a study in two schools located near an international airport in Taiwan. Sixth-grade students (N = 242) were recruited from two schools and were classified into high-and low-noise-exposure groups, based on environmental noise measurements. Person-equivalent 24-h noise exposure was measured to determine noise exposure at the individual level, and it was compared with hearing threshold level and with aircraft noise measured at the environmental level. Individual hearing threshold levels did not differ between environmental high- and low-noise-exposure groups, as evidenced by the lack of difference between the two groups for noise exposure measured at the individual level. However, the proportion of students who were annoyed by aircraft noise was higher in the environmental high-noise-exposure group, although personal 24-h noise exposure was not a factor for annoyance. The results indicated that environmental noise measurement was not an appropriate criterion for assessment of auditory damage (or noise-induced hearing loss) in Taiwan. As well, aircraft-noise exposure in Taiwan did not appear to affect the hearing threshold but nonetheless annoyed school children near the airport. 21 refs., 3 tabs.

  7. Polyurethane Masks Large Areas in Electroplating

    NASA Technical Reports Server (NTRS)

    Beasley, J. L.

    1985-01-01

    Polyurethane foam provides effective mask in electroplating of copper or nickel. Thin layer of Turco maskant painted on area to be masked: Layer ensures polyurethane foam removed easily after served its purpose. Component A, isocyanate, and component B, polyol, mixed together and brushed or sprayed on mask area. Mixture reacts, yielding polyurethane foam. Foam prevents deposition of nickel or copper on covered area. New method saves time, increases productivity and uses less material than older procedures.

  8. [A new bite block for laryngeal mask].

    PubMed

    Ohe, Y; Ota, M; Tachibana, C; Aoyama, Y

    2001-05-01

    We devised a new bite block made of a used connector of anesthesia machine (ACOMA medical industry CO., LTD.) for laryngeal mask. Fitness for laryngeal mask and strength against patient's biting are the key for its use. Cutting lengthwise the connector (the outside diameter 22 mm, inside diameter 15-19 mm, 55 mm in length) we made a bite block for laryngeal mask. We studied the strength of a new bite block experimentally and recognized its ability to bear the human biting. We conclude a new bite block for laryngeal mask is clinically useful and can be used during anesthesia for its fitness and safety.

  9. Temporal masking of multidimensional tactual stimuli

    NASA Astrophysics Data System (ADS)

    Tan, Hong Z.; Reed, Charlotte M.; Delhorne, Lorraine A.; Durlach, Nathaniel I.; Wan, Natasha

    2003-12-01

    Experiments were performed to examine the temporal masking properties of multidimensional tactual stimulation patterns delivered to the left index finger. The stimuli consisted of fixed-frequency sinusoidal motions in the kinesthetic (2 or 4 Hz), midfrequency (30 Hz), and cutaneous (300 Hz) frequency ranges. Seven stimuli composed of one, two, or three spectral components were constructed at each of two signal durations (125 or 250 ms). Subjects identified target signals under three different masking paradigms: forward masking, backward masking, and sandwiched masking (in which the target is presented between two maskers). Target identification was studied as a function of interstimulus interval (ISI) in the range 0 to 640 ms. For both signal durations, percent-correct scores increased with ISI for each of the three masking paradigms. Scores with forward and backward masking were similar and significantly higher than scores obtained with sandwiched masking. Analyses of error trials revealed that subjects showed a tendency to respond, more often than chance, with the masker, the composite of the masker and target, or the combination of the target and a component of the masker. The current results are compared to those obtained in previous studies of tactual recognition masking with brief cutaneous spatial patterns. The results are also discussed in terms of estimates of information transfer (IT) and IT rate, are compared to previous studies with multidimensional tactual signals, and are related to research on the development of tactual aids for the deaf.

  10. Evaluation of a native vegetation masking technique

    NASA Technical Reports Server (NTRS)

    Kinsler, M. C.

    1984-01-01

    A crop masking technique based on Ashburn's vegetative index (AVI) was used to evaluate native vegetation as an indicator of crop moisture condition. A mask of the range areas (native vegetation) was generated for each of thirteen Great Plains LANDSAT MSS sample segments. These masks were compared to the digitized ground truth and accuracies were computed. An analysis of the types of errors indicates a consistency in errors among the segments. The mask represents a simple quick-look technique for evaluating vegetative cover.

  11. Mask lithography for display manufacturing

    NASA Astrophysics Data System (ADS)

    Sandstrom, T.; Ekberg, P.

    2010-05-01

    The last ten years have seen flat displays conquer our briefcases, desktops, and living rooms. There has been an enormous development in production technology, not least in lithography and photomasks. Current masks for large displays are more than 2 m2 and make 4-6 1X prints on glass substrates that are 9 m2. One of the most challenging aspects of photomasks for displays is the so called mura, stripes or blemishes which cause visible defects in the finished display. For the future new and even tighter maskwriter specifications are driven by faster transistors and more complex pixel layouts made necessary by the market's wish for still better image quality, multi-touch panels, 3D TVs, and the next wave of e-book readers. Large OLED screens will pose new challenges. Many new types of displays will be lowcost and use simple lithography, but anything which can show video and high quality photographic images needs a transistor backplane and sophisticated masks for its production.

  12. X-ray lithography masking

    NASA Technical Reports Server (NTRS)

    Smith, Henry I. (Inventor); Lim, Michael (Inventor); Carter, James (Inventor); Schattenburg, Mark (Inventor)

    1998-01-01

    X-ray masking apparatus includes a frame having a supporting rim surrounding an x-ray transparent region, a thin membrane of hard inorganic x-ray transparent material attached at its periphery to the supporting rim covering the x-ray transparent region and a layer of x-ray opaque material on the thin membrane inside the x-ray transparent region arranged in a pattern to selectively transmit x-ray energy entering the x-ray transparent region through the membrane to a predetermined image plane separated from the layer by the thin membrane. A method of making the masking apparatus includes depositing back and front layers of hard inorganic x-ray transparent material on front and back surfaces of a substrate, depositing back and front layers of reinforcing material on the back and front layers, respectively, of the hard inorganic x-ray transparent material, removing the material including at least a portion of the substrate and the back layers of an inside region adjacent to the front layer of hard inorganic x-ray transparent material, removing a portion of the front layer of reinforcing material opposite the inside region to expose the surface of the front layer of hard inorganic x-ray transparent material separated from the inside region by the latter front layer, and depositing a layer of x-ray opaque material on the surface of the latter front layer adjacent to the inside region.

  13. Evaluating Texture Compression Masking Effects Using Objective Image Quality Assessment Metrics.

    PubMed

    Griffin, Wesley; Olano, Marc

    2015-08-01

    Texture compression is widely used in real-time rendering to reduce storage and bandwidth requirements. Recent research in compression algorithms has explored both reduced fixed bit rate and variable bit rate algorithms. The results are evaluated at the individual texture level using mean square error, peak signal-to-noise ratio, or visual image inspection. We argue this is the wrong evaluation approach. Compression artifacts in individual textures are likely visually masked in final rendered images and this masking is not accounted for when evaluating individual textures. This masking comes from both geometric mapping of textures onto models and the effects of combining different textures on the same model such as diffuse, gloss, and bump maps. We evaluate final rendered images using rigorous perceptual error metrics. Our method samples the space of viewpoints in a scene, renders the scene from each viewpoint using variations of compressed textures, and then compares each to a ground truth using uncompressed textures from the same viewpoint. We show that masking has a significant effect on final rendered image quality, masking effects and perceptual sensitivity to masking varies by the type of texture, graphics hardware compression algorithms are too conservative, and reduced bit rates are possible while maintaining final rendered image quality.

  14. Ecology of acoustic signalling and the problem of masking interference in insects.

    PubMed

    Schmidt, Arne K D; Balakrishnan, Rohini

    2015-01-01

    The efficiency of long-distance acoustic signalling of insects in their natural habitat is constrained in several ways. Acoustic signals are not only subjected to changes imposed by the physical structure of the habitat such as attenuation and degradation but also to masking interference from co-occurring signals of other acoustically communicating species. Masking interference is likely to be a ubiquitous problem in multi-species assemblages, but successful communication in natural environments under noisy conditions suggests powerful strategies to deal with the detection and recognition of relevant signals. In this review we present recent work on the role of the habitat as a driving force in shaping insect signal structures. In the context of acoustic masking interference, we discuss the ecological niche concept and examine the role of acoustic resource partitioning in the temporal, spatial and spectral domains as sender strategies to counter masking. We then examine the efficacy of different receiver strategies: physiological mechanisms such as frequency tuning, spatial release from masking and gain control as useful strategies to counteract acoustic masking. We also review recent work on the effects of anthropogenic noise on insect acoustic communication and the importance of insect sounds as indicators of biodiversity and ecosystem health.

  15. Active noise control for infant incubators.

    PubMed

    Yu, Xun; Gujjula, Shruthi; Kuo, Sen M

    2009-01-01

    This paper presents an active noise control system for infant incubators. Experimental results show that global noise reduction can be achieved for infant incubator ANC systems. An audio-integration algorithm is presented to introduce a healthy audio (intrauterine) sound with the ANC system to mask the residual noise and soothe the infant. Carbon nanotube based transparent thin film speaker is also introduced in this paper as the actuator for the ANC system to generate the destructive secondary sound, which can significantly save the congested incubator space and without blocking the view of doctors and nurses.

  16. Masked speech perception across the adult lifespan: Impact of age and hearing impairment.

    PubMed

    Goossens, Tine; Vercammen, Charlotte; Wouters, Jan; van Wieringen, Astrid

    2017-02-01

    As people grow older, speech perception difficulties become highly prevalent, especially in noisy listening situations. Moreover, it is assumed that speech intelligibility is more affected in the event of background noises that induce a higher cognitive load, i.e., noises that result in informational versus energetic masking. There is ample evidence showing that speech perception problems in aging persons are partly due to hearing impairment and partly due to age-related declines in cognition and suprathreshold auditory processing. In order to develop effective rehabilitation strategies, it is indispensable to know how these different degrading factors act upon speech perception. This implies disentangling effects of hearing impairment versus age and examining the interplay between both factors in different background noises of everyday settings. To that end, we investigated open-set sentence identification in six participant groups: a young (20-30 years), middle-aged (50-60 years), and older cohort (70-80 years), each including persons who had normal audiometric thresholds up to at least 4 kHz, on the one hand, and persons who were diagnosed with elevated audiometric thresholds, on the other hand. All participants were screened for (mild) cognitive impairment. We applied stationary and amplitude modulated speech-weighted noise, which are two types of energetic maskers, and unintelligible speech, which causes informational masking in addition to energetic masking. By means of these different background noises, we could look into speech perception performance in listening situations with a low and high cognitive load, respectively. Our results indicate that, even when audiometric thresholds are within normal limits up to 4 kHz, irrespective of threshold elevations at higher frequencies, and there is no indication of even mild cognitive impairment, masked speech perception declines by middle age and decreases further on to older age. The impact of hearing

  17. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  18. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  19. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  20. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  1. 42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets... Efficiency Respirators and Combination Gas Masks § 84.1139 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or...

  2. Health Effects of Noise Exposure in Children.

    PubMed

    Stansfeld, Stephen; Clark, Charlotte

    2015-06-01

    Environmental noise exposure, such as road traffic noise and aircraft noise, is associated with a range of health outcomes in children. Children demonstrate annoyance responses to noise, and noise is also related to lower well-being and stress responses, such as increased levels of adrenaline and noradrenaline. Noise does not cause more serious mental health problems, but there is growing evidence for an association with increased hyperactivity symptoms. Studies also suggest that noise might cause changes in cardiovascular functioning, and there is some limited evidence for an effect on low birth weight. There is robust evidence for an effect of school noise exposure on children's cognitive skills such as reading and memory, as well as on standardised academic test scores. Environmental noise does not usually reach levels that are likely to affect children's hearing; however, increasing use of personal electronic devices may leave some children exposed to harmful levels of noise.

  3. The influence of temporally varying noise from seismic air guns on the detection of underwater sounds by seals.

    PubMed

    Sills, Jillian M; Southall, Brandon L; Reichmuth, Colleen

    2017-02-01

    Standard audiometric data are often applied to predict how noise influences hearing. With regard to auditory masking, critical ratios-obtained using tonal signals and flat-spectrum maskers-can be combined with noise spectral density levels derived from 1/3-octave band levels to predict signal amplitudes required for detection. However, the efficacy of this conventional model of masking may vary based on features of the signal and noise in question. The ability of resource managers to quantify masking from intermittent seismic noise is relevant due to widespread geophysical exploration. To address this, spotted and ringed seals with previously measured critical ratios were trained to detect low-frequency tonal signals within seismic pulses recorded 1 and 30 km from an operational air gun array. The conventional model of masking accurately predicted the extent of masking only in certain cases. When noise amplitude varied significantly in time, the results suggested that detection was driven by higher signal-to-noise ratios within time windows shorter than the full signal duration. This study evaluates when it is appropriate to use average noise levels and critical ratios to predict auditory masking experienced by marine mammals, and suggests how masking models can be improved by incorporating time-based analyses of signals and noise.

  4. A social survey on the noise impact in open-plan working environments in China.

    PubMed

    Zhang, Mei; Kang, Jian; Jiao, Fenglei

    2012-11-01

    The aim of this study is to reveal noise impact in open-plan working environments in China, through a series of questionnaire surveys and acoustic measurements in typical open-plan working environments. It has been found that compared to other physical environmental factors in open-plan working environments, people are much less satisfied with the acoustic environment. The noise impact in the surveyed working environments is rather significant, in terms of sound level inside the office, understanding of colleagues' conversation, and the use of background music such as music players. About 30-50% of the interviewees think that various noise sources inside and outside offices are 'very disturbing' and 'disturbing', and the most annoying sounds include noises from outside, ventilation systems, office equipment, and keyboard typing. Using higher panels to separate work space, or working in enclosed offices, are regarded as effective improvement measures, whereas introducing natural sounds to mask unwanted sounds seems to be not preferable. There are significant correlations between the evaluation of acoustic environment and office symptoms, including hypersensitivity to loud sounds, easily getting tired and depression. There are also significant correlations between evaluation of various acoustics-related factors and certain statements relating to job satisfaction, including sensitivity to noise, as well as whether conversations could be heard by colleagues.

  5. Set Size and Mask Duration Do Not Interact in Object-Substitution Masking

    ERIC Educational Resources Information Center

    Argyropoulos, Ioannis; Gellatly, Angus; Pilling, Michael; Carter, Wakefield

    2013-01-01

    Object-substitution masking (OSM) occurs when a mask, such as four dots that surround a brief target item, onsets simultaneously with the target and offsets a short time after the target, rather than simultaneously with it. OSM is a reduction in accuracy of reporting the target with the temporally trailing mask, compared with the simultaneously…

  6. Variations in backward masking with different masking stimuli: I. Local interaction versus attentional switch.

    PubMed

    Bachmann, Talis; Luiga, Iiris; Põder, Endel

    2005-01-01

    The types of stimuli used as targets and masks considerably change the masking functions in a way that requires us to abandon any single mechanism of masking as the sole explanation of backward masking. In the first of two reports in which the problem of the mask-dependence of masking is addressed, we explore the role of the relative spatial positioning of targets and masks in order to differentiate between local interaction and attentional models. If single letters were masked by double-letter masks then the relative spatial arrangement of the letters, which was changed in order to vary the involvement of metacontrast-like processes, had an effect at shorter SOAs, but not at longer SOAs where strong masking still persisted. This poses difficulties for proposing local contour interaction as the main mechanism of masking. Similarly, crowding effects alone cannot explain the results. Backward masking also involves attention being directed to working-memory processing of the succeeding object while abandoning the preceding object.

  7. Alternating phase-shifted mask for logic gate levels, design, and mask manufacturing

    NASA Astrophysics Data System (ADS)

    Liebmann, Lars W.; Graur, Ioana C.; Leipold, William C.; Oberschmidt, James M.; O'Grady, David S.; Regaill, Denis

    1999-07-01

    While the benefits of alternating phase shifted masks in improving lithographic process windows at increased resolution are well known throughout the lithography community, broad implementation of this potentially powerful technique has been slow due to the inherent complexity of the layout design and mask manufacturing process. This paper will review a project undertaken at IBM's Semiconductor Research and Development Center and Mask Manufacturing and Development facility to understand the technical and logistical issues associated with the application of alternating phase shifted mask technology to the gate level of a full microprocessor chip. The work presented here depicts an important milestone toward integration of alternating phase shifted masks into the manufacturing process by demonstrating an automated design solution and yielding a functional alternating phase shifted mask. The design conversion of the microprocessor gate level to a conjugate twin shifter alternating phase shift layout was accomplished with IBM's internal design system that automatically scaled the design, added required phase regions, and resolved phase conflicts. The subsequent fabrication of a nearly defect free phase shifted mask, as verified by SEM based die to die inspection, highlights the maturity of the alternating phase shifted mask manufacturing process in IBM's internal mask facility. Well defined and recognized challenges in mask inspection and repair remain and the layout of alternating phase shifted masks present a design and data preparation overhead, but the data presented here demonstrate the feasibility of designing and building manufacturing quality alternating phase shifted masks for the gate level of a microprocessor.

  8. EUVL masks: paving the path for commercialization

    NASA Astrophysics Data System (ADS)

    Mangat, Pawitter J. S.; Hector, Scott D.

    2001-09-01

    Optical projection lithography has been the principal vehicle of semiconductor manufacturing for more than 20 years and is marching aggressively to satisfy the needs of semiconductor manufacturers for 100nm devices. However, the complexity of optical lithography continues to increase as wavelength reduction continues to 157nm. Extreme Ultraviolet Lithography (EUVL), with wavelength from 13-14 nm, is evolving as a leading next generation lithography option for semiconductor industry to stay on the path laid by Moore's Law. Masks are a critical part of the success of any technology and are considered to be high risk both for optical lithography and NGL technologies for sub-100nm lithography. Two key areas of EUV mask fabrication are reflective multilayer deposition and absorber patterning. In the case of reflective multilayers, delivering defect free multilayers for mask blanks is the biggest challenge. Defect mitigation is being explored as a possible option to smooth the multilayer defects in addition to optimization of the deposition process to reduce defect density. The mask patterning process needs focus on the defect-free absorber stack patterning process, mask cleaning, inspection and repair. In addition, there is considerable effort to understand by simulations, the defect printability, thermal and mechanical distortions, and non-telecentric illumination, to mention a few. To protect the finished mask from defects added during use, a removable pellicle strategy combined with thermophoretic protection during exposure is being developed. Recent migration to square form factor using low thermal expansion material (LTEM) is advantageous as historical developments in optical masks can be applied to EUV mask patterning. This paper addresses recent developments in the EUV mask patterning and highlights critical manufacturing process controls needed to fabricate defect-free full field masks with CD and image placement specifications for sub-70nm node lithography. No

  9. EUV mask cleans comparison of frontside and dual-sided concurrent cleaning

    NASA Astrophysics Data System (ADS)

    Cheong, Lin Lee; Kindt, Louis; Turley, Christina; Leonhard, Dusty; Boyle, John; Robinson, Chris; Rankin, Jed; Corliss, Daniel

    2015-03-01

    The cleaning requirements for EUV masks are more complex than optical masks due to the absence of available EUVcompatible pellicles. EUV masks must therefore be capable of undergoing more than 100 cleaning cycles with minimum impact to lithographic performance. EUV masks are created on substrates with 40 multilayers of silicon and molybdenum to form a Bragg reflector, capped with a 2.5nm-thick ruthenium layer and a tantalum-based absorber; during usage, both ruthenium and absorber are exposed to the cleaning process. The CrN layer on the backside is used to enable electrostatic clamping. This clamp side must also be free of particles that could impact printing and overlay, and particles could also potentially migrate to the frontside and create defects. Thus, the cleaning process must provide decent particle removal efficiencies on both front- and backside while maintaining reflectivity with minimal surface roughness change. In this paper, we report progress developing a concurrent patterned-side and clamped-side cleaning process that achieves minimal reflectivity change over 120 cleaning cycles, with XPS and EDS indicating the presence of ruthenium after 125 cleaning cycles. The change in surface roughness over 100 cleaning cycles is within the noise (0.0086nm) on a mask blank, and SEM inspection of 100nm and 200nm features on patterned masks after undergoing 100 cleaning cycles show no indications of ruthenium pitting or significant surface damage. This process was used on test masks to remove particles from both sides that would otherwise inhibit these masks from being used in the scanner.

  10. Helicopter external noise requirements: FAA perspective

    NASA Technical Reports Server (NTRS)

    Foster, C. R.

    1978-01-01

    Enactment of helicopter noise certification standards for the control of noise impact contributing to community annoyance is considered in terms of the development of helicopters as an environmentally compatible air transportation mode. Increased use of helicopters for commercial applications and public awareness of aircraft noise are cited as factors making development of helicopter noise standards necessary both for the protection of the environmental interest of the community and to ensure the orderly growth of the helicopter industry itself. Noise sources, technology trends in helicopter design, and design concepts to control helicopter noise are discussed along with the regulatory background and specific helicopter regulatory concepts.

  11. A facial mask comprising Dead Sea mud.

    PubMed

    Abu-Jdayil, Basim; Mohameed, Hazim A

    2006-01-01

    Many investigators have proved that Dead Sea salt and mud are useful in treating skin disorders and skin diseases. Therefore, the black mud has been extensively used as a base for the preparation of soaps, creams, and unguents for skin care. This study concerns a facial mask made mainly of Dead Sea mud. The effects of temperature and shearing conditions on the rheological behavior of the facial mask were investigated. The mud facial mask exhibited a shear thinning behavior with a yield stress. It was found that the apparent viscosity of the mask has a strong dependence on the shear rate as well as on the temperature. The facial mask exhibited a maximum yield stress and very shear thinning behavior at 40 degrees C, which is attributed to the gelatinization of the polysaccharide used to stabilize the mud particles. On the other hand, the mud mask exhibited a time-independent behavior at low temperatures and shear rates and changed to a thixotropic behavior upon increasing both the temperature and the shear rate. The shear thinning and thixotropic behaviors have a significant importance in the ability of the facial mask to spread on the skin: the Dead Sea mud mask can break down for easy spreading, and the applied film can gain viscosity instantaneously to resist running. Moreover, particle sedimentation, which in this case would negatively affect consumer acceptance of the product, occurs slowly due to high viscosity at rest conditions.

  12. 21 CFR 868.5590 - Scavenging mask.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Scavenging mask. 868.5590 Section 868.5590 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5590 Scavenging mask. (a) Identification....

  13. 21 CFR 868.5570 - Nonrebreathing mask.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonrebreathing mask. 868.5570 Section 868.5570 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5570 Nonrebreathing mask....

  14. Spatial processing and visual backward masking.

    PubMed

    Herzog, Michael H

    2008-07-15

    Most theories of visual masking focus prima-rily on the temporal aspects of visual information processing, strongly neglecting spatial factors. In recent years, however, we have shown that this position is not tenable. Spatial aspects cannot be neglected in metacontrast, pattern and un-masking. Here, we review these results.

  15. Spatial processing and visual backward masking

    PubMed Central

    Herzog, Michael H.

    2008-01-01

    Most theories of visual masking focus prima-rily on the temporal aspects of visual information processing, strongly neglecting spatial factors. In recent years, however, we have shown that this position is not tenable. Spatial aspects cannot be neglected in metacontrast, pattern and un-masking. Here, we review these results. PMID:20517500

  16. Masking the Feeling of Being Stupid.

    ERIC Educational Resources Information Center

    Smith, Sally L.

    1988-01-01

    Teaching experience at The Lab School of Washington has shown that learning-disabled children and adults cope with their lack of self-esteem and feelings of stupidity by developing masks to hide their hurt. These include masks of super-competence, helplessness, invisibility, clowning, injustice collecting, indifference, boredom, outrageousness,…

  17. Implicit Semantic Perception in Object Substitution Masking

    ERIC Educational Resources Information Center

    Goodhew, Stephanie C.; Visser, Troy A. W.; Lipp, Ottmar V.; Dux, Paul E.

    2011-01-01

    Decades of research on visual perception has uncovered many phenomena, such as binocular rivalry, backward masking, and the attentional blink, that reflect "failures of consciousness". Although stimuli do not reach awareness in these paradigms, there is evidence that they nevertheless undergo semantic processing. Object substitution masking (OSM),…

  18. Computing Challenges in Coded Mask Imaging

    NASA Technical Reports Server (NTRS)

    Skinner, Gerald

    2009-01-01

    This slide presaentation reviews the complications and challenges in developing computer systems for Coded Mask Imaging telescopes. The coded mask technique is used when there is no other way to create the telescope, (i.e., when there are wide fields of view, high energies for focusing or low energies for the Compton/Tracker Techniques and very good angular resolution.) The coded mask telescope is described, and the mask is reviewed. The coded Masks for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) instruments are shown, and a chart showing the types of position sensitive detectors used for the coded mask telescopes is also reviewed. Slides describe the mechanism of recovering an image from the masked pattern. The correlation with the mask pattern is described. The Matrix approach is reviewed, and other approaches to image reconstruction are described. Included in the presentation is a review of the Energetic X-ray Imaging Survey Telescope (EXIST) / High Energy Telescope (HET), with information about the mission, the operation of the telescope, comparison of the EXIST/HET with the SWIFT/BAT and details of the design of the EXIST/HET.

  19. Observations and Modeling of Seismic Background Noise

    USGS Publications Warehouse

    Peterson, Jon R.

    1993-01-01

    TERRAscope network deployed by the California Institute of Technology in cooperation with other institutions. A map showing the approximate locations of the stations used in this study is provided in Figure 1. One might hope for a better distribution of stations in the southern hemisphere, especially Africa and South America, in order to look for regional variations in seismic noise (apart from the major differences between continental, coastal and island sites). Unfortunately, anyone looking for subtle regional variations in seismic noise is probably going to be disappointed by the spectral data presented in this report because much of the station data appear to be dominated by local disturbances caused by instrumental, environmental, cultural, or surf noise. Better instruments and better instrument siting, or a well-funded field program, will be needed before a global isoseismal noise map can be produced. However, by assembling a composite of background noise from a large network of stations, many of the local station variables are masked, and it is possible to create generalized spectral plots of Earth noise for hypothetical quiet and noisy station sites.

  20. A Novel Anti-Influenza Copper Oxide Containing Respiratory Face Mask

    PubMed Central

    Borkow, Gadi; Zhou, Steve S.; Page, Tom; Gabbay, Jeffrey

    2010-01-01

    may significantly reduce the risk of hand or environmental contamination, and thereby subsequent infection, due to improper handling and disposal of the masks. PMID:20592763

  1. Interior Noise

    NASA Technical Reports Server (NTRS)

    Mixson, John S.; Wilby, John F.

    1991-01-01

    The generation and control of flight vehicle interior noise is discussed. Emphasis is placed on the mechanisms of transmission through airborne and structure-borne paths and the control of cabin noise by path modification. Techniques for identifying the relative contributions of the various source-path combinations are also discussed along with methods for the prediction of aircraft interior noise such as those based on the general modal theory and statistical energy analysis.

  2. Noise Assessment Guidelines.

    ERIC Educational Resources Information Center

    Schultz, Theodore J.; McMahon, Nancy M.

    The Department of Housing and Urban Development (HUD), in its efforts to provide decent housing and a suitable living environment, is concerned with noise as a major source of environmental pollution. To this end, these guidelines are presented to provide site screening techniques. The procedures described have been developed so that people…

  3. The influence of informational masking on speech perception and pupil response in adults with hearing impairment.

    PubMed

    Koelewijn, Thomas; Zekveld, Adriana A; Festen, Joost M; Kramer, Sophia E

    2014-03-01

    A recent pupillometry study on adults with normal hearing indicates that the pupil response during speech perception (cognitive processing load) is strongly affected by the type of speech masker. The current study extends these results by recording the pupil response in 32 participants with hearing impairment (mean age 59 yr) while they were listening to sentences masked by fluctuating noise or a single-talker. Efforts were made to improve audibility of all sounds by means of spectral shaping. Additionally, participants performed tests measuring verbal working memory capacity, inhibition of interfering information in working memory, and linguistic closure. The results showed worse speech reception thresholds for speech masked by single-talker speech compared to fluctuating noise. In line with previous results for participants with normal hearing, the pupil response was larger when listening to speech masked by a single-talker compared to fluctuating noise. Regression analysis revealed that larger working memory capacity and better inhibition of interfering information related to better speech reception thresholds, but these variables did not account for inter-individual differences in the pupil response. In conclusion, people with hearing impairment show more cognitive load during speech processing when there is interfering speech compared to fluctuating noise.

  4. Nasal mask ventilation is better than face mask ventilation in edentulous patients

    PubMed Central

    Kapoor, Mukul Chandra; Rana, Sandeep; Singh, Arvind Kumar; Vishal, Vindhya; Sikdar, Indranil

    2016-01-01

    Background and Aims: Face mask ventilation of the edentulous patient is often difficult as ineffective seating of the standard mask to the face prevents attainment of an adequate air seal. The efficacy of nasal ventilation in edentulous patients has been cited in case reports but has never been investigated. Material and Methods: Consecutive edentulous adult patients scheduled for surgery under general anesthesia with endotracheal intubation, during a 17-month period, were prospectively evaluated. After induction of anesthesia and administration of neuromuscular blocker, lungs were ventilated with a standard anatomical face mask of appropriate size, using a volume controlled anesthesia ventilator with tidal volume set at 10 ml/kg. In case of inadequate ventilation, the mask position was adjusted to achieve best-fit. Inspired and expired tidal volumes were measured. Thereafter, the face mask was replaced by a nasal mask and after achieving best-fit, the inspired and expired tidal volumes were recorded. The difference in expired tidal volumes and airway pressures at best-fit with the use of the two masks and number of patients with inadequate ventilation with use of the masks were statistically analyzed. Results: A total of 79 edentulous patients were recruited for the study. The difference in expiratory tidal volumes with the use of the two masks at best-fit was statistically significant (P = 0.0017). Despite the best-fit mask placement, adequacy of ventilation could not be achieved in 24.1% patients during face mask ventilation, and 12.7% patients during nasal mask ventilation and the difference was statistically significant. Conclusion: Nasal mask ventilation is more efficient than standard face mask ventilation in edentulous patients. PMID:27625477

  5. Fully phase image encryption using double random-structured phase masks in gyrator domain.

    PubMed

    Singh, Hukum; Yadav, A K; Vashisth, Sunanda; Singh, Kehar

    2014-10-01

    We propose a method for fully phase image encryption based on double random-structured phase mask encoding in the gyrator transform (GT) domain. The security of the system is strengthened by parameters used in the construction of a structured phase mask (SPM) based on a devil's vortex Fresnel lens (DVFL). The input image is recovered using the correct parameters of the SPMs, transform orders of the GT, and conjugate of the random phase masks. The use of a DVFL-based SPM enhances security by increasing the key space for encryption, and also overcomes the problem of axis alignment associated with an optical setup. The proposed scheme can also be implemented optically. The computed values of mean squared error between the retrieved and the original image show the efficacy of the proposed scheme. We have also investigated the scheme's sensitivity to the encryption parameters, and robustness against occlusion and multiplicative Gaussian noise attacks.

  6. Amplitude-phase retrieval attack free image encryption based on two random masks and interference

    NASA Astrophysics Data System (ADS)

    Liansheng, Sui; bei, Zhou; Zhanmin, Wang; qindong, Sun

    2016-11-01

    An amplitude-phase retrieval attack free encryption scheme is proposed by using two random masks, where one is considered as the random image and other as the public key. Initially, the random image is encrypted to two phase-only masks based on interference technique with the help of the public key. These two phase-only masks are real-valued functions and used as the encryption keys. Then, the plain image is encrypted to the ciphertext with the white noise distribution by using the phase-truncated Fourier-transform-based encoding scheme with the previous encryption keys. The encryption process is nonlinear in which no iterative calculation is involved, while the decryption process is linear which can be easily implemented with the 4 f optical system. Moreover, less constraints makes the specific attack unusable. Simulation results are given to verify the feasibility and robustness of the proposed encryption scheme.

  7. SNR analysis and Hadamard mask modification of DMD Hadamard Transform Near-Infrared spectrometer

    NASA Astrophysics Data System (ADS)

    Xu, Jia-lin; Liu, Hua; Lin, Chun-bo; Sun, Qiang

    2017-01-01

    The noise of Hadamard Transform (HT) Near Infrared (NIR) spectrometer includes not only the detector circuit noise but also the illumination noise. Hadamard Transform reduces the detector noise while increases the illumination noise. If the relative power intensity is large, the noise of Hadamard method will be greater than that of scanning method. This will lose the significance of Hadamard Transform. In this paper the SNRs of the Hadamard method and scanning method are analyzed. The condition of boosting SNR of spectrometer by Hadamard transform is given. When the condition is not matched, a Hadamard mask of variable height stripes is proposed which the SNR of Hadamard method can be improved. In this paper a HT NIR spectrometer based on 0.45-inch DMD is designed with the spectrum range from 1350 nm to 2500 nm. Several experiments are done with the designed spectrometer. It is shown that with the Hadamard mask of variable height stripes the average SNR is improved by a factor of 2.2 at the short wavelength band and by a factor of 2.8 on the long wavelength band, and the minimum SNR on the whole wavelength band is improved by a factor of 2.3.

  8. Masking property of quantum random cipher with phase mask encryption

    NASA Astrophysics Data System (ADS)

    Sohma, Masaki; Hirota, Osamu

    2014-10-01

    The security analysis of physical encryption protocol based on coherent pulse position modulation (CPPM) originated by Yuen is one of the most interesting topics in the study of cryptosystem with a security level beyond the Shannon limit. Although the implementation of CPPM scheme has certain difficulty, several methods have been proposed recently. This paper deals with the CPPM encryption in terms of symplectic transformation, which includes a phase mask encryption as a special example, and formulates a unified security analysis for such encryption schemes. Specifically, we give a lower bound of Eve's symbol error probability using reliability function theory to ensure that our proposed system exceeds the Shannon limit. Then we assume the secret key is given to Eve after her heterodyne measurement. Since this assumption means that Eve has a great advantage in the sense of the conventional cryptography, the lower bound of her error indeed ensures the security level beyond the Shannon limit. In addition, we show some numerical examples of the security performance.

  9. Effect of low-frequency gain reduction on speech recognition and its relation to upward spread of masking.

    PubMed

    Cook, J A; Bacon, S P; Sammeth, C A

    1997-04-01

    Speech recognition was measured in listeners with normal hearing and in listeners with sensorineural hearing loss under conditions that simulated hearing aid processing in a low-pass and speech-shaped background noise. Differing amounts of low-frequency gain reduction were applied during a high-frequency monosyllable test and a sentence level test to simulate the frequency responses of some commercial hearing aids. The results showed an improvement in speech recognition with low-frequency gain reduction in the low-pass noise, but not in the speech-shaped background noise. Masking patterns also were obtained with the two background noises at 70 and 80 dB SPL to compare with the speech results. There was no correlation observed between the masking results and the improvement in speech recognition with low-frequency gain reduction.

  10. Neural correlates of binaural masking level difference in the inferior colliculus of the barn owl (Tyto alba).

    PubMed

    Asadollahi, Ali; Endler, Frank; Nelken, Israel; Wagner, Hermann

    2010-08-01

    Humans and animals are able to detect signals in noisy environments. Detection improves when the noise and the signal have different interaural phase relationships. The resulting improvement in detection threshold is called the binaural masking level difference. We investigated neural mechanisms underlying the release from masking in the inferior colliculus of barn owls in low-frequency and high-frequency neurons. A tone (signal) was presented either with the same interaural time difference as the noise (masker) or at a 180 degrees phase shift as compared with the interaural time difference of the noise. The changes in firing rates induced by the addition of a signal of increasing level while masker level was kept constant was well predicted by the relative responses to the masker and signal alone. In many cases, the response at the highest signal levels was dominated by the response to the signal alone, in spite of a significant response to the masker at low signal levels, suggesting the presence of occlusion. Detection thresholds and binaural masking level differences were widely distributed. The amount of release from masking increased with increasing masker level. Narrowly tuned neurons in the central nucleus of the inferior colliculus had detection thresholds that were lower than or similar to those of broadly tuned neurons in the external nucleus of the inferior colliculus. Broadly tuned neurons exhibited higher masking level differences than narrowband neurons. These data suggest that detection has different spectral requirements from localization.

  11. Achievements and challenges of EUV mask imaging

    NASA Astrophysics Data System (ADS)

    Davydova, Natalia; van Setten, Eelco; de Kruif, Robert; Connolly, Brid; Fukugami, Norihito; Kodera, Yutaka; Morimoto, Hiroaki; Sakata, Yo; Kotani, Jun; Kondo, Shinpei; Imoto, Tomohiro; Rolff, Haiko; Ullrich, Albrecht; Lammers, Ad; Schiffelers, Guido; van Dijk, Joep

    2014-07-01

    The impact of various mask parameters on CDU combined in a total mask budget is presented, for 22 nm lines, for reticles used for NXE:3300 qualification. Apart from the standard mask CD measurements, actinic spectrometry of multilayer is used to qualify reflectance uniformity over the image field; advanced 3D metrology is applied for absorber profile characterization including absorber height and side wall angle. The predicted mask impact on CDU is verified using actual exposure data collected on multiple NXE:3300 scanners. Mask 3D effects are addressed, manifesting themselves in best focus shifts for different structures exposed with off-axis illumination. Experimental NXE:3300 results for 16 nm dense lines and 20 nm (semi-)isolated spaces are shown: best focus range reaches 24 nm. A mitigation strategy by absorber height optimization is proposed based on experimental results of a special mask with varying absorber heights. Further development of a black image border for EUV mask is considered. The image border is a pattern free area surrounding image field preventing exposure the image field neighborhood on wafer. Normal EUV absorber is not suitable for this purpose as it has 1-3% EUV reflectance. A current solution is etching of ML down to substrate reducing EUV reflectance to <0.05%. A next step in the development of the black border is the reduction of DUV Out-of-Band reflectance (<1.5%) in order to cope with DUV light present in EUV scanners. Promising results achieved in this direction are shown.

  12. Mask Fabrication Using Electron Beam Exposure System

    NASA Astrophysics Data System (ADS)

    Watakabe, Y.; Shigetomi, A.; Morimoto, H.; Kato, T.

    1981-07-01

    This study describes the results of feature size distribution, pattern location accuracy and level to level registration error on chrominum master masks fabricated by EeBES-40. This system has the capability of high speed electron beam blanking at 40MHz, the capacity for large size masks (with 6 inch mask cassette), and the automatic cassette handling system. OEBR-100(PGMA), as the electron beam negative resist, is used for 5 inch and 6 inch chrominum masks. The chrominum etching process is used for both wet and dry plasma technology. Test patterns and 64 K bit memory TEG, as the practical pattern, are used in this study. More than 40 measurements are taken, uniformly distributed over 96 to 112mm square, and the feature size distribution is measured by a laser interferometer X-Y measuring system. Pattern location accuracy and level to level registration error are obtained using EeBES-40 quality assurance programs called MARKET/PLOTMARKET. This program operates by scanning over the resist image of the test pattern, utilizing the normal fiducial mark location hardware. The followinc results are obtained; (1) Feature size distribution within 6 inch mask : -/+0.1 μm (2) Level-to-level registration error2 : less than 0.1 pm High quality masks with about 0.02 defects/cm2 , and rapid throughput of 6 hr./10 masks using the auto-matic 10-cassette handling system are obtained.

  13. Reflective masks for extreme ultraviolet lithography

    SciTech Connect

    Nguyen, Khanh Bao

    1994-05-01

    Extreme ultraviolet lithographic masks are made by patterning multilayer reflective coatings with high normal incidence reflectivity. Masks can be patterned by depositing a patterned absorber layer above the coating or by etching the pattern directly into the coating itself. Electromagnetic simulations showed that absorber-overlayer masks have superior imaging characteristics over etched masks (less sensitive to incident angles and pattern profiles). In an EUVL absorber overlayer mask, defects can occur in the mask substrate, reflective coating, and absorber pattern. Electromagnetic simulations showed that substrate defects cause the most severe image degradation. A printability study of substrate defects for absorber overlayer masks showed that printability of 25 nm high substrate defects are comparable to defects in optical lithography. Simulations also indicated that the manner in which the defects are covered by multilayer reflective coatings can affect printability. Coverage profiles that result in large lateral spreading of defect geometries amplify the printability of the defects by increasing their effective sizes. Coverage profiles of Mo/Si coatings deposited above defects were studied by atomic force microscopy and TEM. Results showed that lateral spread of defect geometry is proportional to height. Undercut at defect also increases the lateral spread. Reductions in defect heights were observed for 0.15 μm wide defect lines. A long-term study of Mo/Si coating reflectivity revealed that Mo/Si coatings with Mo as the top layer suffer significant reductions in reflectivity over time due to oxidation.

  14. Intact crowding and temporal masking in dyslexia.

    PubMed

    Doron, Adi; Manassi, Mauro; Herzog, Michael H; Ahissar, Merav

    2015-01-01

    Phonological deficits in dyslexia are well documented. However, there is an ongoing discussion about whether visual deficits limit the reading skills of people with dyslexia. Here, we investigated visual crowding and backward masking. We presented a Vernier (i.e., two vertical bars slightly offset to the left or right) and asked observers to indicate the offset direction. Vernier stimuli are visually similar to letters and are strongly affected by crowding, even in the fovea. To increase task difficulty, Verniers are often followed by a mask (i.e., backward masking). We measured Vernier offset discrimination thresholds for the basic Vernier task, under crowding, and under backward masking, in students with dyslexia (n = 19) and age and intelligence matched students (n = 27). We found no group differences in any of these conditions. Controls with fast visual processing (good backward masking performance), were faster readers. By contrast, no such correlation was found among the students with dyslexia, suggesting that backward masking does not limit their reading efficiency. These findings indicate that neither elevated crowding nor elevated backward masking pose a bottleneck to reading skills of people with dyslexia.

  15. Noise policy: Past and present

    NASA Astrophysics Data System (ADS)

    Lang, William W.

    2004-05-01

    Leo Beranek and the firm Bolt Beranek and Newman have played a defining role in the formulation of noise policy in America. The firm that he and Richard Bolt founded in 1948 with fewer than a half-dozen others grew to become the world's largest acoustical consulting firm with more than 2000 employees. Two decades later in 1971, Leo Beranek was a key founder of the Institute of Noise Control Engineering of the U.S.A. The Institute, which inaugurated the INTER-NOISE series of annual noise congresses in 1972 under Beranek's direction, played a major role in the enactment by the Congress of the Noise Control Act of 1972. NCA-72 identified the Environmental Protection Agency as the leading Federal agency with oversight responsibilities responsible for implementing the noise policies defined by the Congress. In 1981, funding for EPA's noise program was withdrawn. Since then, leadership at the Federal level for implementing a coordinated national noise policy has been absent, but a dozen Federal agencies remain active in the noise field. With the exception of aircraft, no product emission regulations on major sources of noise are enforced today. To rectify this situation, Leo Beranek has recently been playing a leadership role in a concerted effort to rejuvenate America's national noise policy.

  16. Application of Polynomial and Radial Basis Function Maps to Signal Masking

    SciTech Connect

    Damiano, B.

    1998-01-01

    The objective of this research was to develop and demonstrate a technique for encrypting information by using a masking signal that closely approximates local ambient noise. Signal masking techniques developed to date have used nonlinear differential equations, spread spectrum, and various modulation schemes to encode information. While these techniques can effectively hide a signal, the resulting masks may not appear as ambient noise to an observer. The advantage of the proposed technique over commonly used masking methods is that the transmitted signal will appear as normal background noise, thus greatly reducing the probability of detection and exploitation. A promising near-term application of this technology presents itself in the area of clandestine minefield reconnaissance in shallow water areas. Shallow water mine-counter-mine (SWMCM) activity is essential for minefield avoidance, efficient minefield clearance, and effective selection of transit lanes within minefields. A key technology area for SWMCM is the development of special sonar waveforms with low probability of exploitation/intercept (LPE/LPI) attributes. In addition to LPE/LPI sonar, this technology has the potential to enable significant improvements in underwater acoustic communications. For SWMCM, the chaotic waveform research provides a mechanism for encrypted communications between a submarine (SSN) and an unmanned underwater vehicle (UUV) via an acoustic channel. Acoustic SSN/UUV communications would eliminate the need for a fiberoptic link between the two vessels, thus increasing the robustness of SWMCM. Similar applications may exist in the areas of radar masking and secure communications. The original approach called for the use of polynomial maps to generate a masking signal. Because polynomial maps were found to have highly restrictive stability criteria, the approach was modified to use radial basis function (RBF) maps. they have shown that stable RBF maps that closely approximate an

  17. When Bad Masks Turn Good

    NASA Astrophysics Data System (ADS)

    Abraham, Roberto G.

    In keeping with the spirit of a meeting on ‘masks,' this talk presents two short stories on the theme of dust. In the first, dust plays the familiar role of the evil obscurer, the enemy to bedefeated by the cunning observer in order to allow a key future technology (adaptive optics) to be exploited fully by heroic astronomers. In the second story, dust itself emerges as the improbable hero, in the form of a circumstellar debris disks. I will present evidence of a puzzling near-infrared excess in the continuum of high-redshift galaxies and will argue that the seemingly improbable origin of this IR excess is a population of young circumstellar disks formed around high-mass stars in distant galaxies. Assuming circumstellar disks extend down to lower masses,as they do in our own Galaxy, the excess emission presents us with an exciting opportunity to measure the formation rate of planetary systems in distant galaxies at cosmic epochs before our own solar system formed.

  18. X-Ray Lithography Mask Metrology: Use of Transmitted Electrons in an SEM for Linewidth Measurement

    PubMed Central

    Postek, Michael T.; Lowney, Jeremiah R.; Vladar, Andras E.; Keery, William J.; Marx, Egon; Larrabee, Robert D.

    1993-01-01

    X-ray masks present a measurement object that is different from most other objects used in semiconductor processing because the support membrane is, by design, x-ray transparent. This characteristic can be used as an advantage in electron beam-based x-ray mask metrology since, depending upon the incident electron beam energies, substrate composition and substrate thickness, the membrane can also be essentially electron transparent. The areas of the mask where the absorber structures are located are essentially x-ray opaque, as well as electron opaque. This paper shows that excellent contrast and signal-to-noise levels can be obtained using the transmitted-electron signal for mask metrology rather than the more commonly collected secondary electron signal. Monte Carlo modeling of the transmitted electron signal was used to support this work in order to determine the optimum detector position and characteristics, as well as in determining the location of the edge in the image profile. The comparison between the data from the theoretically-modeled electron beam interaction and actual experimental data were shown to agree extremely well, particularly with regard to the wall slope characteristics of the structure. Therefore, the theory can be used to identify the location of the edge of the absorber line for linewidth measurement. This work provides one approach to improved x-ray mask linewidth metrology and a more precise edge location algorithm for measurement of feature sizes on x-ray masks in commercial instrumentation. This work also represents an initial step toward the first SEM-based accurate linewidth measurement standard from NIST, as well as providing a viable metrology for linewidth measurement instruments of x-ray masks for the lithography community. PMID:28053482

  19. Informational masking of speech in children: Effects of ipsilateral and contralateral distracters

    NASA Astrophysics Data System (ADS)

    Wightman, Frederic L.; Kistler, Doris J.

    2005-11-01

    Using a closed-set speech recognition paradigm thought to be heavily influenced by informational masking, auditory selective attention was measured in 38 children (ages 4-16 years) and 8 adults (ages 20-30 years). The task required attention to a monaural target speech message that was presented with a time-synchronized distracter message in the same ear. In some conditions a second distracter message or a speech-shaped noise was presented to the other ear. Compared to adults, children required higher target/distracter ratios to reach comparable performance levels, reflecting more informational masking in these listeners. Informational masking in most conditions was confirmed by the fact that a large proportion of the errors made by the listeners were contained in the distracter message(s). There was a monotonic age effect, such that even the children in the oldest age group (13.6-16 years) demonstrated poorer performance than adults. For both children and adults, presentation of an additional distracter in the contralateral ear significantly reduced performance, even when the distracter messages were produced by a talker of different sex than the target talker. The results are consistent with earlier reports from pure-tone masking studies that informational masking effects are much larger in children than in adults.

  20. Auditory Masking Effects on Speech Fluency in Apraxia of Speech and Aphasia: Comparison to Altered Auditory Feedback

    ERIC Educational Resources Information Center

    Jacks, Adam; Haley, Katarina L.

    2015-01-01

    Purpose: To study the effects of masked auditory feedback (MAF) on speech fluency in adults with aphasia and/or apraxia of speech (APH/AOS). We hypothesized that adults with AOS would increase speech fluency when speaking with noise. Altered auditory feedback (AAF; i.e., delayed/frequency-shifted feedback) was included as a control condition not…

  1. A positron emission tomography study of the neural basis of informational and energetic masking effects in speech perception

    NASA Astrophysics Data System (ADS)

    Scott, Sophie K.; Rosen, Stuart; Wickham, Lindsay; Wise, Richard J. S.

    2004-02-01

    Positron emission tomography (PET) was used to investigate the neural basis of the comprehension of speech in unmodulated noise (``energetic'' masking, dominated by effects at the auditory periphery), and when presented with another speaker (``informational'' masking, dominated by more central effects). Each type of signal was presented at four different signal-to-noise ratios (SNRs) (+3, 0, -3, -6 dB for the speech-in-speech, +6, +3, 0, -3 dB for the speech-in-noise), with listeners instructed to listen for meaning to the target speaker. Consistent with behavioral studies, there was SNR-dependent activation associated with the comprehension of speech in noise, with no SNR-dependent activity for the comprehension of speech-in-speech (at low or negative SNRs). There was, in addition, activation in bilateral superior temporal gyri which was associated with the informational masking condition. The extent to which this activation of classical ``speech'' areas of the temporal lobes might delineate the neural basis of the informational masking is considered, as is the relationship of these findings to the interfering effects of unattended speech and sound on more explicit working memory tasks. This study is a novel demonstration of candidate neural systems involved in the perception of speech in noisy environments, and of the processing of multiple speakers in the dorso-lateral temporal lobes.

  2. A study of defects on EUV mask using blank inspection, patterned mask inspection, and wafer inspection

    SciTech Connect

    Huh, S.; Ren, L.; Chan, D.; Wurm, S.; Goldberg, K. A.; Mochi, I.; Nakajima, T.; Kishimoto, M.; Ahn, B.; Kang, I.; Park, J.-O.; Cho, K.; Han, S.-I.; Laursen, T.

    2010-03-12

    The availability of defect-free masks remains one of the key challenges for inserting extreme ultraviolet lithography (EUVL) into high volume manufacturing. yet link data is available for understanding native defects on real masks. In this paper, a full-field EUV mask is fabricated to investigate the printability of various defects on the mask. The printability of defects and identification of their source from mask fabrication to handling were studied using wafer inspection. The printable blank defect density excluding particles and patterns is 0.63 cm{sup 2}. Mask inspection is shown to have better sensitivity than wafer inspection. The sensitivity of wafer inspection must be improved using through-focus analysis and a different wafer stack.

  3. Durations required to distinguish noise and tone: Effects of noise bandwidth and frequency.

    PubMed

    Taghipour, Armin; Moore, Brian C J; Edler, Bernd

    2016-05-01

    Perceptual audio coders exploit the masking properties of the human auditory system to reduce the bit rate in audio recording and transmission systems; it is intended that the quantization noise is just masked by the audio signal. The effectiveness of the audio signal as a masker depends on whether it is tone-like or noise-like. The determination of this, both physically and perceptually, depends on the duration of the stimuli. To gather information that might improve the efficiency of perceptual coders, the duration required to distinguish between a narrowband noise and a tone was measured as a function of center frequency and noise bandwidth. In experiment 1, duration thresholds were measured for isolated noise and tone bursts. In experiment 2, duration thresholds were measured for tone and noise segments embedded within longer tone pulses. In both experiments, center frequencies were 345, 754, 1456, and 2658 Hz and bandwidths were 0.25, 0.5, and 1 times the equivalent rectangular bandwidth of the auditory filter at each center frequency. The duration thresholds decreased with increasing bandwidth and with increasing center frequency up to 1456 Hz. It is argued that the duration thresholds depended mainly on the detection of amplitude fluctuations in the noise bursts.

  4. Active Mask Segmentation of Fluorescence Microscope Images

    PubMed Central

    Srinivasa, Gowri; Fickus, Matthew C.; Guo, Yusong; Linstedt, Adam D.; Kovačević, Jelena

    2009-01-01

    We propose a new active mask algorithm for the segmentation of fluorescence microscope images of punctate patterns. It combines the (a) flexibility offered by active-contour methods, (b) speed offered by multiresolution methods, (c) smoothing offered by multiscale methods, and (d) statistical modeling offered by region-growing methods into a fast and accurate segmentation tool. The framework moves from the idea of the “contour” to that of “inside and outside”, or, masks, allowing for easy multidimensional segmentation. It adapts to the topology of the image through the use of multiple masks. The algorithm is almost invariant under initialization, allowing for random initialization, and uses a few easily tunable parameters. Experiments show that the active mask algorithm matches the ground truth well, and outperforms the algorithm widely used in fluorescence microscopy, seeded watershed, both qualitatively as well as quantitatively. PMID:19380268

  5. Masking properties of APD communication systems

    NASA Astrophysics Data System (ADS)

    Fernandez, J. G.; Larrondo, H. A.; Slavin, H. A.; Levin, D. G.; Hidalgo, R. M.; Rivera, R. R.

    2003-10-01

    In this paper, we explore the ability of wavelet multilevel analysis to unmask the information hidden in a chaotic mask. This digital filtering technique has been recently reported as particularly well suited for the detection of coherent structures. In a recent paper the capability of wavelets to unmask a message, in cases where a chaotic signal is just added to the information, has also been demonstrated. The case of an active passive decomposition scheme, where message is mixed with the chaotic signal, is studied here. A representative case employing Daubechies wavelets and a typical Rossler-oscillator-based communication system is reported. Using a time scaling parameter modifies the spectrum of the mask. The results show that wavelets are effective only in particular cases with poor masking. The fast Fourier transform analysis demonstrates that the spectrum of the chaotic mask shows no holes and then other digital filtering techniques such as Wiener filters or comb filters must also been disregarded.

  6. Correction of deflection under mask's own weight by bending mask technology

    NASA Astrophysics Data System (ADS)

    Yagami, Takashi; Kambayashi, Takashi; Azumi, Minako

    2016-10-01

    It is known that the photomask substrate deflects when the mask is set on the frame and the deflection is an obstacle to light exposure. In this study, we introduce "the bending mask" to cancel out the deflection. The surface of the bending mask has the height distribution in advance to cancel out the deflection, owing to Nikon's accurate polishing technology and Nikon's accurate measurement machine.

  7. Inspection of lithographic mask blanks for defects

    DOEpatents

    Sommargren, Gary E.

    2001-01-01

    A visible light method for detecting sub-100 nm size defects on mask blanks used for lithography. By using optical heterodyne techniques, detection of the scattered light can be significantly enhanced as compared to standard intensity detection methods. The invention is useful in the inspection of super-polished surfaces for isolated surface defects or particulate contamination and in the inspection of lithographic mask or reticle blanks for surface defects or bulk defects or for surface particulate contamination.

  8. Achromatic phase shifting focal plane masks

    NASA Astrophysics Data System (ADS)

    Newman, Kevin

    The search for life on other worlds is an exciting scientific endeavor that could change the way we perceive our place in the universe. Thousands of extrasolar planets have been discovered using indirect detection techniques. One of the most promising methods for discovering new exoplanets and searching for life is direct imaging with a coronagraph. Exoplanet coronagraphy of Earth-like planets is a challenging task, but we have developed many of the tools necessary to make it feasible. The Phase-Induced Amplitude Apodization (PIAA) Coronagraph is one of the highest-performing architectures for direct exoplanet imaging. With a complex phase-shifting focal plane mask, the PIAA Complex Mask Coronagraph (PIAACMC) can approach the theoretical performance limit for any direct detection technique. The architecture design is flexible enough to be applied to any arbitrary aperture shape, including segmented and obscured apertures. This is an important feature for compatibility with next-generation ground and space-based telescopes. PIAA and PIAACMC focal plane masks have been demonstrated in monochromatic light. An important next step for high-performance coronagraphy is the development of broadband phase-shifting focal plane masks. In this dissertation, we present an algorithm for designing the PIAA and PIAACMC focal plane masks to operate in broadband. We also demonstrate manufacturing of the focal plane masks, and show laboratory results. We use simulations to show the potential performance of the coronagraph system, and the use of wavefront control to correct for mask manufacturing errors. Given the laboratory results and simulations, we show new areas of exoplanet science that can potentially be explored using coronagraph technology. The main conclusion of this dissertation is that we now have the tools required to design and manufacture PIAA and PIAACMC achromatic focal plane masks. These tools can be applied to current and future telescope systems to enable new

  9. An overview of health effects on noise

    NASA Astrophysics Data System (ADS)

    Osada, Y.

    1988-12-01

    Although noise can damage the inner ear and cause other pathological changes, its most common negative effects are non-somatic, such as a perception of noisiness and disturbance of daily activities. According to the definition of health by WHO, this should be considered as a health hazard. These health effects of noise can be classified into the following three categories: (I) hearing loss, perception of noisiness and masking are produced along the auditory pathway and are thus direct and specific effects of noise; (II) interference with performance, rest and sleep, a feeling of discomfort and some physiological effects are produced as indirect and non-specific effects via reticular formation of the midbrain; (III) annoyance is not merely a feeling of unpleasantness but the feeling of being bothered or troubled, and includes the development of a particular attitude toward the noise source. Individual or group behavioral responses will be evoked when annoyance develops. Annoyance and behavioral response are integrated and composite effects. The health effects of noise are modified by many factors related to both the noise and the individual. Noise level, frequency spectrum, duration and impulsiveness modify the effects. Sex, age, health status and mental character also have an influence on the effects. Direct effects of noise are most dependent on the physical nature of the noise and least dependent on human factors. Indirect effects are more dependent, and integrated effects most dependent, on human factors.

  10. Robust watermark technique using masking and Hermite transform.

    PubMed

    Coronel, Sandra L Gomez; Ramírez, Boris Escalante; Mosqueda, Marco A Acevedo

    2016-01-01

    The following paper evaluates a watermark algorithm designed for digital images by using a perceptive mask and a normalization process, thus preventing human eye detection, as well as ensuring its robustness against common processing and geometric attacks. The Hermite transform is employed because it allows a perfect reconstruction of the image, while incorporating human visual system properties; moreover, it is based on the Gaussian functions derivates. The applied watermark represents information of the digital image proprietor. The extraction process is blind, because it does not require the original image. The following techniques were utilized in the evaluation of the algorithm: peak signal-to-noise ratio, the structural similarity index average, the normalized crossed correlation, and bit error rate. Several watermark extraction tests were performed, with against geometric and common processing attacks. It allowed us to identify how many bits in the watermark can be modified for its adequate extraction.

  11. No masking between test and mask components in perceptually different depth planes.

    PubMed

    Hibbeler, Patrick J; Olzak, Lynn A

    2011-01-01

    2-D cues to perceived depth organization have been used to segregate test and mask stimulus components in a discrimination task. Observers made either spatial-frequency or orientation judgments on a rectangular test component by itself or in the presence of constant rectangular masks. There were two basic masking conditions: same-plane or different-plane. In the same-plane conditions, the test components and masks are perceived as existing in the same depth plane. In the different-plane conditions, the test and mask components are perceived to exist in different depth planes. The perception of different depth planes was achieved by using perceived occlusion, which could place either component closer or further from the observer. The results suggest that when test and mask components are separated into different depth planes they no longer influence one another. This effect could be observed in either depth organization, test components in front of the masks or mask components in front of the test. These results indicate that the figure-ground organization of components is not important. Only the designation as existing in the same or different depth planes affects whether or not a mask is effective.

  12. Mask cost of ownership for advanced lithography

    NASA Astrophysics Data System (ADS)

    Muzio, Edward G.; Seidel, Philip K.

    2000-07-01

    As technology advances, becoming more difficult and more expensive, the cost of ownership (CoO) metric becomes increasingly important in evaluating technical strategies. The International SEMATECH CoC analysis has steadily gained visibility over the past year, as it attempts to level the playing field between technology choices, and create a fair relative comparison. In order to predict mask cots for advanced lithography, mask process flows are modeled using bets-known processing strategies, equipment cost, and yields. Using a newly revised yield mode, and updated mask manufacture flows, representative mask flows can be built. These flows are then used to calculate mask costs for advanced lithography down to the 50 nm node. It is never the goal of this type of work to provide absolute cost estimates for business planning purposes. However, the combination of a quantifiable yield model with a clearly defined set of mask processing flows and a cost model based upon them serves as an excellent starting point for cost driver analysis and process flow discussion.

  13. VSP wave separation by adaptive masking filters

    NASA Astrophysics Data System (ADS)

    Rao, Ying; Wang, Yanghua

    2016-06-01

    In vertical seismic profiling (VSP) data processing, the first step might be to separate the down-going wavefield from the up-going wavefield. When using a masking filter for VSP wave separation, there are difficulties associated with two termination ends of the up-going waves. A critical challenge is how the masking filter can restore the energy tails, the edge effect associated with these terminations uniquely exist in VSP data. An effective strategy is to implement masking filters in both τ-p and f-k domain sequentially. Meanwhile it uses a median filter, producing a clean but smooth version of the down-going wavefield, used as a reference data set for designing the masking filter. The masking filter is implemented adaptively and iteratively, gradually restoring the energy tails cut-out by any surgical mute. While the τ-p and the f-k domain masking filters target different depth ranges of VSP, this combination strategy can accurately perform in wave separation from field VSP data.

  14. Dopamine receptor D4 (DRD4) gene modulates the influence of informational masking on speech recognition

    PubMed Central

    Xie, Zilong; Maddox, W. Todd; Knopik, Valerie S.; McGeary, John E.; Chandrasekaran, Bharath

    2014-01-01

    Listeners vary substantially in their ability to recognize speech in noisy environments. Here we examined the role of genetic variation on individual differences in speech recognition in various noise backgrounds. Background noise typically varies in the levels of energetic masking (EM) and informational masking (IM) imposed on target speech. Relative to EM, release from IM is hypothesized to place greater demand on executive function to selectively attend to target speech while ignoring competing noises. Recent evidence suggests that the long allele variant in exon III of the DRD4 gene, primarily expressed in the prefrontal cortex, may be associated with enhanced selective attention to goal-relevant high-priority information even in the face of interference. We investigated the extent to which this polymorphism is associated with speech recognition in IM and EM conditions. In an unscreened adult sample (Experiment 1) and a larger screened replication sample (Experiment 2), we demonstrate that individuals with the DRD4 long variant show better recognition performance in noise conditions involving significant IM, but not in EM conditions. In Experiment 2, we also obtained neuropsychological measures to assess the underlying mechanisms. Mediation analyses revealed that this listening condition-specific advantage was mediated by enhanced executive attention/working memory capacity in individuals with the long allele variant. These findings suggest that DRD4 may contribute specifically to individual differences in speech recognition ability in noise conditions that place demands on executive function. PMID:25497692

  15. Dopamine receptor D4 (DRD4) gene modulates the influence of informational masking on speech recognition.

    PubMed

    Xie, Zilong; Maddox, W Todd; Knopik, Valerie S; McGeary, John E; Chandrasekaran, Bharath

    2015-01-01

    Listeners vary substantially in their ability to recognize speech in noisy environments. Here we examined the role of genetic variation on individual differences in speech recognition in various noise backgrounds. Background noise typically varies in the levels of energetic masking (EM) and informational masking (IM) imposed on target speech. Relative to EM, release from IM is hypothesized to place greater demand on executive function to selectively attend to target speech while ignoring competing noises. Recent evidence suggests that the long allele variant in exon III of the DRD4 gene, primarily expressed in the prefrontal cortex, may be associated with enhanced selective attention to goal-relevant high-priority information even in the face of interference. We investigated the extent to which this polymorphism is associated with speech recognition in IM and EM conditions. In an unscreened adult sample (Experiment 1) and a larger screened replication sample (Experiment 2), we demonstrate that individuals with the DRD4 long variant show better recognition performance in noise conditions involving significant IM, but not in EM conditions. In Experiment 2, we also obtained neuropsychological measures to assess the underlying mechanisms. Mediation analysis revealed that this listening condition-specific advantage was mediated by enhanced executive attention/working memory capacity in individuals with the long allele variant. These findings suggest that DRD4 may contribute specifically to individual differences in speech recognition ability in noise conditions that place demands on executive function.

  16. A cloud masking algorithm for EARLINET lidar systems

    NASA Astrophysics Data System (ADS)

    Binietoglou, Ioannis; Baars, Holger; D'Amico, Giuseppe; Nicolae, Doina

    2015-04-01

    Cloud masking is an important first step in any aerosol lidar processing chain as most data processing algorithms can only be applied on cloud free observations. Up to now, the selection of a cloud-free time interval for data processing is typically performed manually, and this is one of the outstanding problems for automatic processing of lidar data in networks such as EARLINET. In this contribution we present initial developments of a cloud masking algorithm that permits the selection of the appropriate time intervals for lidar data processing based on uncalibrated lidar signals. The algorithm is based on a signal normalization procedure using the range of observed values of lidar returns, designed to work with different lidar systems with minimal user input. This normalization procedure can be applied to measurement periods of only few hours, even if no suitable cloud-free interval exists, and thus can be used even when only a short period of lidar measurements is available. Clouds are detected based on a combination of criteria including the magnitude of the normalized lidar signal and time-space edge detection performed using the Sobel operator. In this way the algorithm avoids misclassification of strong aerosol layers as clouds. Cloud detection is performed using the highest available time and vertical resolution of the lidar signals, allowing the effective detection of low-level clouds (e.g. cumulus humilis). Special attention is given to suppress false cloud detection due to signal noise that can affect the algorithm's performance, especially during day-time. In this contribution we present the details of algorithm, the effect of lidar characteristics (space-time resolution, available wavelengths, signal-to-noise ratio) to detection performance, and highlight the current strengths and limitations of the algorithm using lidar scenes from different lidar systems in different locations across Europe.

  17. 42 CFR 84.117 - Gas mask containers; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Gas mask containers; minimum requirements. 84.117... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.117 Gas mask containers; minimum requirements. (a) Gas masks shall be equipped with a...

  18. 42 CFR 84.117 - Gas mask containers; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Gas mask containers; minimum requirements. 84.117... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.117 Gas mask containers; minimum requirements. (a) Gas masks shall be equipped with a...

  19. 42 CFR 84.117 - Gas mask containers; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Gas mask containers; minimum requirements. 84.117... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.117 Gas mask containers; minimum requirements. (a) Gas masks shall be equipped with a...

  20. 42 CFR 84.117 - Gas mask containers; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Gas mask containers; minimum requirements. 84.117... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.117 Gas mask containers; minimum requirements. (a) Gas masks shall be equipped with a...

  1. Out of Their Heads: Developing the Character behind the Mask.

    ERIC Educational Resources Information Center

    Lecure, Bruce

    1996-01-01

    Discusses mask building as a theatrical exercise. Provides a simple method for building masks. Outlines a format for the classes that follow mask construction, in which a character is gradually built to suit the finished mask, including the birthing process, physical character and voice development, getting to know the character, and what happens…

  2. 21 CFR 868.5560 - Gas mask head strap.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Gas mask head strap. 868.5560 Section 868.5560...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5560 Gas mask head strap. (a) Identification. A gas mask head strap is a device used to hold an anesthetic gas mask in position on a...

  3. 21 CFR 868.5560 - Gas mask head strap.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Gas mask head strap. 868.5560 Section 868.5560...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5560 Gas mask head strap. (a) Identification. A gas mask head strap is a device used to hold an anesthetic gas mask in position on a...

  4. 21 CFR 868.5560 - Gas mask head strap.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Gas mask head strap. 868.5560 Section 868.5560...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5560 Gas mask head strap. (a) Identification. A gas mask head strap is a device used to hold an anesthetic gas mask in position on a...

  5. 21 CFR 868.5560 - Gas mask head strap.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gas mask head strap. 868.5560 Section 868.5560...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5560 Gas mask head strap. (a) Identification. A gas mask head strap is a device used to hold an anesthetic gas mask in position on a...

  6. 21 CFR 868.5560 - Gas mask head strap.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Gas mask head strap. 868.5560 Section 868.5560...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5560 Gas mask head strap. (a) Identification. A gas mask head strap is a device used to hold an anesthetic gas mask in position on a...

  7. 37 CFR 211.3 - Mask work fees.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Mask work fees. 211.3 Section... PROCEDURES MASK WORK PROTECTION § 211.3 Mask work fees. (a) Section 201.3 of this chapter prescribes the fees or charges established by the Register of Copyrights for services relating to mask works. (b)...

  8. En route noise of two turboprop aircraft

    NASA Technical Reports Server (NTRS)

    Dobrzynski, Werner

    1990-01-01

    In order to weigh en route noise emissions originating from future propfan powered aircraft, a data base of emission levels from conventional turboprop aircraft is needed. For this reason flyover noise measurements on two twin-engine turboprop aircraft were conducted at flight heights between 17,000 and 21,000 ft. Acoustic data are presented together with propeller operational parameters and environmental meteorological data. Narrowband spectral analyses demonstrate the characteristic features of the measured propeller noise signatures: Noise spectra are dominated by the propeller rotational noise fundamental frequency and pronounced noise beats occur as a consequence of different rotational speeds of the propellers.

  9. Influence of Transportation Noise and Noise Sensitivity on Annoyance: A Cross-Sectional Study in South Korea

    PubMed Central

    Sung, Joo Hyun; Lee, Jiho; Jeong, Kyoung Sook; Lee, Soogab; Lee, Changmyung; Jo, Min-Woo; Sim, Chang Sun

    2017-01-01

    Environmental noise is known to cause noise annoyance. Since noise annoyance is a subjective indicator, other mediators—such as noise sensitivity—may influence its perception. However, few studies have thus far been conducted on noise annoyance in South Korea that consider noise sensitivity and noise level simultaneously. The aim of this study was to evaluate the correlations between noise sensitivity or noise level and noise annoyance on a large scale in South Korea. This study estimated the level of noise exposure based on a noise map created in 2014; identified and surveyed 1836 subjects using a questionnaire; and assessed the impact of transportation noise and noise sensitivity on noise annoyance. The result showed that noise exposure level and noise sensitivity simultaneously affect noise annoyance, and noise sensitivity has a relatively larger impact on noise annoyance. In conclusion, when study subjects were exposed to a similar level of noise, the level of noise annoyance differed depending on the noise sensitivity of the individual. PMID:28335543

  10. Ligand-induced Epitope Masking

    PubMed Central

    Mould, A. Paul; Askari, Janet A.; Byron, Adam; Takada, Yoshikazu; Jowitt, Thomas A.; Humphries, Martin J.

    2016-01-01

    We previously demonstrated that Arg-Gly-Asp (RGD)-containing ligand-mimetic inhibitors of integrins are unable to dissociate pre-formed integrin-fibronectin complexes (IFCs). These observations suggested that amino acid residues involved in integrin-fibronectin binding become obscured in the ligand-occupied state. Because the epitopes of some function-blocking anti-integrin monoclonal antibodies (mAbs) lie near the ligand-binding pocket, it follows that the epitopes of these mAbs may become shielded in the ligand-occupied state. Here, we tested whether function-blocking mAbs directed against α5β1 can interact with the integrin after it forms a complex with an RGD-containing fragment of fibronectin. We showed that the anti-α5 subunit mAbs JBS5, SNAKA52, 16, and P1D6 failed to disrupt IFCs and hence appeared unable to bind to the ligand-occupied state. In contrast, the allosteric anti-β1 subunit mAbs 13, 4B4, and AIIB2 could dissociate IFCs and therefore were able to interact with the ligand-bound state. However, another class of function-blocking anti-β1 mAbs, exemplified by Lia1/2, could not disrupt IFCs. This second class of mAbs was also distinguished from 13, 4B4, and AIIB2 by their ability to induce homotypic cell aggregation. Although the epitope of Lia1/2 was closely overlapping with those of 13, 4B4, and AIIB2, it appeared to lie closer to the ligand-binding pocket. A new model of the α5β1-fibronectin complex supports our hypothesis that the epitopes of mAbs that fail to bind to the ligand-occupied state lie within, or very close to, the integrin-fibronectin interface. Importantly, our findings imply that the efficacy of some therapeutic anti-integrin mAbs could be limited by epitope masking. PMID:27484800

  11. Optical inspection of EPL stencil masks

    NASA Astrophysics Data System (ADS)

    Welsh, James; McCallum, Martin; Okada, Masashi

    2003-06-01

    We are now at a major junction in lithography where non-optical lithographies, such as Electron Projection Lithography (EPL) [1], are being introduced. The mask used in EPL is a non-transparent silicon substrate with a thin silicon (~2μm) membrane with openings for electrons to pass through acting as a scatterer. This must be inspected as defects may cause printable defects. Initial mask inspection work has used SEM inspection to find these defects. However, we have historically used optical mask inspection tools, utilising wavelengths at or above what we are using for imaging, to qualify masks. This technology has been increasingly difficult to sustain as we have moved from imaging using mercury lamp based sources to pulsed excimer laser based sources that are not very suited to the inspection imaging. Indeed, review of defects found has moved from optical microscopes to SEM based tools. Inspection tools have also evolved, with the first SEM based mask inspection tools being developed to find the smallest defects, however these have the penalty of very low throughput. We will show the potential of using optical systems for the transmissive inspection of these EPL masks. The high potential of existing tools will be shown together with the need for a next generation of inspection tools. We will show that simulations indicate that an inspection source with 193nm wavelength would be required for the detection of 50nm defects on a mask used to print 70nm dense lines. It will also be shown how the position of the defect within the membrane greatly influences detection as well as the implications of moving to a thinner silicon membrane.

  12. The Intervenor Effect in Masked Priming: How Does Masked Priming Survive across an Intervening Word?

    ERIC Educational Resources Information Center

    Forster, Kenneth I.

    2009-01-01

    Four masked priming experiments are reported investigating the effect of inserting an unrelated word between the masked prime and the target. When the intervening word is visible, identity priming is reduced to the level of one-letter-different form priming, but form priming is largely unaffected. However, when the intervening word is itself…

  13. Spatial release from masking improves sound pattern discrimination along a biologically relevant pulse-rate continuum in gray treefrogs

    PubMed Central

    Ward, Jessica L.; Buerkle, Nathan P.; Bee, Mark A.

    2013-01-01

    Frogs form large choruses during the mating season in which males produce loud advertisement calls to attract females and repel rival males. High background noise levels in these social aggregations can impair vocal perception. In humans, spatial release from masking contributes to our ability to understand speech in noisy social groups. Here, we tested the hypothesis that spatial separation between target signals and ‘chorus-shaped noise’ improves the ability of female gray treefrogs (Hyla chrysoscelis) to perform a behavioral discrimination task based on perceiving differences in the pulsatile structure of advertisement calls. We used two-stimulus choice tests to measure phonotaxis (approach toward sound) in response to calls differing in pulse rate along a biologically relevant continuum between conspecific (50 pulses s−1) and heterospecific (20 pulses s−1) calls. Signals were presented in quiet, in colocated noise, and in spatially separated noise. In quiet conditions, females exhibited robust preferences for calls with relatively faster pulse rates more typical of conspecific calls. Behavioral discrimination between calls differing in pulse rate was impaired in the presence of colocated noise but similar between quiet and spatially separated noise conditions. Our results indicate that spatial release from energetic masking facilitates a biologically important temporal discrimination task in frogs. We discuss these results in light of previous work on spatial release from masking in frogs and other animals. PMID:24055623

  14. Evaluation of optimal masking levels in place-specific low-frequency chirp-evoked auditory brainstem responses.

    PubMed

    Baljić, Izet; Eßer, Dirk; Foerst, Astrid; Walger, Martin

    2017-01-01

    The aim of the study is the experimental determination of the optimal required masking level for a given stimulus level when using a band limited "low-frequency chirp" in order to improve frequency and place specificity of auditory brainstem responses (ABRs). A low-frequency chirp (100-850 Hz) at stimulation levels between 40 and 80 dB normalized hearing level was presented to 12 normal hearing subjects. During presentation of each stimulus, the level of a high-pass noise with a low cutoff frequency of 1100 Hz was varied between 0 and 25 dB signal-to-noise ratio (SNR) by using 5 dB steps (at 0 dB SNR the same level of both the chirp and the masker in dB sound pressure level was presented). Measurements without masking were used as a reference. In all masking conditions, the latency of wave V was significantly increased compared to unmasked ABRs. The amplitude of wave V decreased when reaching the effective and therefore optimal masking level. Accordingly, in order to ensure place specificity of the ABR, ipsilateral masking is essential. At lower stimulus levels the SNR can be substantially increased (i.e., the masker level decreased) without loss of place specificity.

  15. When ambient noise impairs parent-offspring communication.

    PubMed

    Lucass, Carsten; Eens, Marcel; Müller, Wendt

    2016-05-01

    Ambient noise has increased in extent, duration and intensity with significant implications for species' lives. Birds especially, because they heavily rely on vocal communication, are highly sensitive towards noise pollution. Noise can impair the quality of a territory or hamper the transmission of vocal signals such as song. The latter has significant fitness consequences as it may erode partner preferences in the context of mate choice. Additional fitness costs may arise if noise masks communication between soliciting offspring and providing parents during the period of parental care. Here, we experimentally manipulated the acoustic environment of blue tit (Cyanistes caeruleus) families within their nest boxes with playbacks of previously recorded highway noise and investigated the consequences on parent-offspring communication. We hypothesized that noise interferes with the acoustic cues of parental arrival and vocal components of offspring begging. As such we expected an increase in the frequency of missed detections, when nestlings fail to respond to the returning parent, and a decrease in parental provisioning rates. Parents significantly reduced their rate of provisioning in noisy conditions compared to a control treatment. This reduction is likely to be the consequence of a parental misinterpretation of the offspring hunger level, as we found that nestlings fail to respond to the returning parent more frequently in the presence of noise. Noise also potentially masks vocal begging components, again contributing to parental underestimation of offspring requirements. Either way, it appears that noise impaired parent-offspring communication is likely to reduce reproductive success.

  16. Fast adaptive unsharp masking with programmable mediaprocessors.

    PubMed

    Bae, Unmin; Shamdasani, Vijay; Managuli, Ravi; Kim, Yongmin

    2003-06-01

    Unsharp masking is a widely used image-enhancement method in medical imaging. Hardware-based solutions can be developed to support high computational demand for unsharp masking, but they suffer from limited flexibility. Software solutions can easily incorporate new features and modify key parameters, such as filtering kernel size, but they have not been able to meet the fast computing requirement. Modern programmable mediaprocessors can meet both fast computing and flexibility requirements, which will benefit medical image computing. In this article, we present fast adaptive unsharp masking on two leading mediaprocessors or high-end digital signal processors, Hitachi/Equator Technologies MAP-CA and Texas Instruments TMS320C64x. For a 2k x 2k 16-bit image, our adaptive unsharp masking with a 201 x 201 boxcar kernel takes 225 ms on a 300-MHz MAP-CA and 74 ms on a 600-MHz TMS320C64x. This fast unsharp masking enables technologists and/or physicians to adjust parameters interactively for optimal quality assurance and image viewing.

  17. Efficient adaptive thresholding with image masks

    NASA Astrophysics Data System (ADS)

    Oh, Young-Taek; Hwang, Youngkyoo; Kim, Jung-Bae; Bang, Won-Chul

    2014-03-01

    Adaptive thresholding is a useful technique for document analysis. In medical image processing, it is also helpful for segmenting structures, such as diaphragms or blood vessels. This technique sets a threshold using local information around a pixel, then binarizes the pixel according to the value. Although this technique is robust to changes in illumination, it takes a significant amount of time to compute thresholds because it requires adding all of the neighboring pixels. Integral images can alleviate this overhead; however, medical images, such as ultrasound, often come with image masks, and ordinary algorithms often cause artifacts. The main problem is that the shape of the summing area is not rectangular near the boundaries of the image mask. For example, the threshold at the boundary of the mask is incorrect because pixels on the mask image are also counted. Our key idea to cope with this problem is computing the integral image for the image mask to count the valid number of pixels. Our method is implemented on a GPU using CUDA, and experimental results show that our algorithm is 164 times faster than a naïve CPU algorithm for averaging.

  18. Spatial Release From Masking in Simulated Cochlear Implant Users With and Without Access to Low-Frequency Acoustic Hearing.

    PubMed

    Williges, Ben; Dietz, Mathias; Hohmann, Volker; Jürgens, Tim

    2015-12-30

    For normal-hearing listeners, speech intelligibility improves if speech and noise are spatially separated. While this spatial release from masking has already been quantified in normal-hearing listeners in many studies, it is less clear how spatial release from masking changes in cochlear implant listeners with and without access to low-frequency acoustic hearing. Spatial release from masking depends on differences in access to speech cues due to hearing status and hearing device. To investigate the influence of these factors on speech intelligibility, the present study measured speech reception thresholds in spatially separated speech and noise for 10 different listener types. A vocoder was used to simulate cochlear implant processing and low-frequency filtering was used to simulate residual low-frequency hearing. These forms of processing were combined to simulate cochlear implant listening, listening based on low-frequency residual hearing, and combinations thereof. Simulated cochlear implant users with additional low-frequency acoustic hearing showed better speech intelligibility in noise than simulated cochlear implant users without acoustic hearing and had access to more spatial speech cues (e.g., higher binaural squelch). Cochlear implant listener types showed higher spatial release from masking with bilateral access to low-frequency acoustic hearing than without. A binaural speech intelligibility model with normal binaural processing showed overall good agreement with measured speech reception thresholds, spatial release from masking, and spatial speech cues. This indicates that differences in speech cues available to listener types are sufficient to explain the changes of spatial release from masking across these simulated listener types.

  19. Spatial Release From Masking in Simulated Cochlear Implant Users With and Without Access to Low-Frequency Acoustic Hearing

    PubMed Central

    Dietz, Mathias; Hohmann, Volker; Jürgens, Tim

    2015-01-01

    For normal-hearing listeners, speech intelligibility improves if speech and noise are spatially separated. While this spatial release from masking has already been quantified in normal-hearing listeners in many studies, it is less clear how spatial release from masking changes in cochlear implant listeners with and without access to low-frequency acoustic hearing. Spatial release from masking depends on differences in access to speech cues due to hearing status and hearing device. To investigate the influence of these factors on speech intelligibility, the present study measured speech reception thresholds in spatially separated speech and noise for 10 different listener types. A vocoder was used to simulate cochlear implant processing and low-frequency filtering was used to simulate residual low-frequency hearing. These forms of processing were combined to simulate cochlear implant listening, listening based on low-frequency residual hearing, and combinations thereof. Simulated cochlear implant users with additional low-frequency acoustic hearing showed better speech intelligibility in noise than simulated cochlear implant users without acoustic hearing and had access to more spatial speech cues (e.g., higher binaural squelch). Cochlear implant listener types showed higher spatial release from masking with bilateral access to low-frequency acoustic hearing than without. A binaural speech intelligibility model with normal binaural processing showed overall good agreement with measured speech reception thresholds, spatial release from masking, and spatial speech cues. This indicates that differences in speech cues available to listener types are sufficient to explain the changes of spatial release from masking across these simulated listener types. PMID:26721918

  20. Removal of bone in CT angiography by multiscale matched mask bone elimination

    SciTech Connect

    Gratama van Andel, H. A. F.; Venema, H. W.; Streekstra, G. J.; Straten, M. van; Majoie, C. B. L. M.; Heeten, G. J. den; Grimbergen, C. A.

    2007-10-15

    For clear visualization of vessels in CT angiography (CTA) images of the head and neck using maximum intensity projection (MIP) or volume rendering (VR) bone has to be removed. In the past we presented a fully automatic method to mask the bone [matched mask bone elimination (MMBE)] for this purpose. A drawback is that vessels adjacent to bone may be partly masked as well. We propose a modification, multiscale MMBE, which reduces this problem by using images at two scales: a higher resolution than usual for image processing and a lower resolution to which the processed images are transformed for use in the diagnostic process. A higher in-plane resolution is obtained by the use of a sharper reconstruction kernel. The out-of-plane resolution is improved by deconvolution or by scanning with narrower collimation. The quality of the mask that is used to remove bone is improved by using images at both scales. After masking, the desired resolution for the normal clinical use of the images is obtained by blurring with Gaussian kernels of appropriate widths. Both methods (multiscale and original) were compared in a phantom study and with clinical CTA data sets. With the multiscale approach the width of the strip of soft tissue adjacent to the bone that is masked can be reduced from 1.0 to 0.2 mm without reducing the quality of the bone removal. The clinical examples show that vessels adjacent to bone are less affected and therefore better visible. Images processed with multiscale MMBE have a slightly higher noise level or slightly reduced resolution compared with images processed by the original method and the reconstruction and processing time is also somewhat increased. Nevertheless, multiscale MMBE offers a way to remove bone automatically from CT angiography images without affecting the integrity of the blood vessels. The overall image quality of MIP or VR images is substantially improved relative to images processed with the original MMBE method.

  1. The requirements for the future e-beam mask writer: statistical analysis of pattern accuracy

    NASA Astrophysics Data System (ADS)

    Lee, Sang Hee; Choi, Jin; Kim, Hee Bom; Kim, Byung Gook; Cho, Han-Ku

    2011-11-01

    As semiconductor features shrink in size and pitch, the extreme control of CD uniformity, MTT and image placement is needed for mask fabrication with e-beam lithography. Among the many sources of CD and image placement error, the error resulting from e-beam mask writer becomes more important than before. CD and positioning error by e-beam mask writer is mainly related to the imperfection of e-beam deflection accuracy in optic system and the charging and contamination of column. To avoid these errors, the e-beam mask writer should be designed taking into account for these effects. However, the writing speed is considered for machine design with the highest priority, because the e-beam shot count is increased rapidly due to design shrink and aggressive OPC. The increment of shot count can make the pattern shift problem due to statistical issue resulting from e-beam deflection error and the total shot count in layout. And it affects the quality of CD and image placement too. In this report, the statistical approach on CD and image placement error caused by e-beam shot position error is presented. It is estimated for various writing conditions including the intrinsic e-beam positioning error of VSB writer. From the simulation study, the required e-beam shot position accuracy to avoid pattern shift problem in 22nm node and beyond is estimated taking into account for total shot count. And the required local CD uniformity is calculated for various e-beam writing conditions. The image placement error is also simulated for various conditions including e-beam writing field position error. Consequently, the requirements for the future e-beam mask writer and the writing conditions are discussed. And in terms of e-beam shot noise, LER caused by exposure dose and shot position error is studied for future e-beam mask writing for 22nm node and beyond.

  2. Noise Pollution Filters Bird Communities Based on Vocal Frequency

    PubMed Central

    Francis, Clinton D.; Ortega, Catherine P.; Cruz, Alexander

    2011-01-01

    Background Human-generated noise pollution now permeates natural habitats worldwide, presenting evolutionarily novel acoustic conditions unprecedented to most landscapes. These acoustics not only harm humans, but threaten wildlife, and especially birds, via changes to species densities, foraging behavior, reproductive success, and predator-prey interactions. Explanations for negative effects of noise on birds include disruption of acoustic communication through energetic masking, potentially forcing species that rely upon acoustic communication to abandon otherwise suitable areas. However, this hypothesis has not been adequately tested because confounding stimuli often co-vary with noise and are difficult to separate from noise exposure. Methodology/Principal Findings Using a natural experiment that controls for confounding stimuli, we evaluate whether species vocal features or urban-tolerance classifications explain their responses to noise measured through habitat use. Two data sets representing nesting and abundance responses reveal that noise filters bird communities nonrandomly. Signal duration and urban tolerance failed to explain species-specific responses, but birds with low-frequency signals that are more susceptible to masking from noise avoided noisy areas and birds with higher frequency vocalizations remained. Signal frequency was also negatively correlated with body mass, suggesting that larger birds may be more sensitive to noise due to the link between body size and vocal frequency. Conclusions/Significance Our findings suggest that acoustic masking by noise may be a strong selective force shaping the ecology of birds worldwide. Larger birds with lower frequency signals may be excluded from noisy areas, whereas smaller species persist via transmission of higher frequency signals. We discuss our findings as they relate to interspecific relationships among body size, vocal amplitude and frequency and suggest that they are immediately relevant to the

  3. Development of an advanced mask and its fabrication system

    NASA Astrophysics Data System (ADS)

    Takigawa, Tadahiro; Tojo, Toru; Ogawa, Yoji; Koyama, Kiyomi; Ono, Akira; Inoue, Soichi; Ito, Shinichi; Goto, Mineo

    1995-07-01

    Masks and their fabrication technologies are keys to the further advancement of optical lithography. A stable SiNx single layer attenuated masks for DUV have been developed. A 0.2 micrometers contact hole pattern was fabricated using a KrF stepper with the SiNx attenuated mask. Toshiba mask fabrication system, including an electron beam writing system, a data base inspection system, and a data conversion system, has been developed for 64 Mbit DRAM class. Required mask improvements for increasing optical lithography resolution include better critical dimension (CD) uniformity, higher mask writing system resolution, and automatic shifter patten generation of alternating phase shifting masks. In addition, improved mask pattern positioning accuracy is also required. In this paper, experimental CD uniformity and resolution improvements, automatic phase shifter assignment method, and improvement in positioning accuracy, are described. The future development of masks will incorporate these key technologies.

  4. Masked hearing thresholds of harbour seals (Phoca vitulina) in air.

    PubMed

    Renouf, D

    1980-10-01

    Two wild seals, maintained in captivity in good health, were trained to swim on verbal command to a spot 27 cm above the water, and subsequently to make a L or R turn to a pure tone vs no tone. White noise was present at 80, 70, or 60 db SPL. Masked thresholds were determined by a staircase method in 2-db steps at 2, 4, 8.6, and 15 kc/s (at 15 kc/s only noise at 60 db SPL was presented). Critical bandwidths in db were calculated, all of the order of 25 db (range of to 28 db). These values are close to those reported by Terhune and Ronald (J. Acoust.Soc.Am., 1975, 58, 515-516) for seals' aerial hearing but are unexplainably lower (i.e., worse) than for seals underwater. It was calculated that in their often noisy and visually restricted natural environment, a mother would not be able to hear her pup if separated by more than 8 m. This situation was generally corroborated by field observation on the breeding grounds.

  5. Protective mask for airborne toxic substances

    SciTech Connect

    Shoemaker, C.J.; Scavnicky, J.A.; Little, M.E.; Hagy, E.M.; Bloom, A.

    1983-10-21

    A protective mask is described which includes a one-piece face piece molded of a transparent elastomer. A visor in the face piece provides panoramic visibility and is resilient enough to deform under applied force to permit improved use of optical devices. Identical left and right cheek fittings permit installation of a canister on either side so that the same mask can be used by right-handed and left-handed wearers voice for use with a telephone and the like. Air deflectors inside the mask adjacent the left and right cheek fittings deflect de-foging air along the inside surface of the visor when either left or right or both cheek fittings are used for attachment of a canister. A sealing adapter permits sealing around earpiece shafts of eyeglasses.

  6. Layer aware source mask target optimization

    NASA Astrophysics Data System (ADS)

    Chen, Ao; Foong, Yee Mei; Schramm, Jessy; Ji, Liang; Hsu, Stephen; Guerrero, James; Li, Xiaoyang; Shaw, Joe; Wang, Joe

    2016-03-01

    In this paper, we present the approach and results of layer-aware source mask target optimization. In this approach, the design target is co-optimized during source mask optimization (SMO) by considering inter-layer constraints. We tested the method on a 2x nm node metal layer by using both standard and customized cost functions for source optimization. Variable targets were defined for two process window limiting critical pattern cells, with contact-to-metal and metal-tovia coverage rules taken into consideration. The results indicate that layer-aware source mask target optimization gives consistent process window improvement over conventional SMO. The optimized targets prove to be a good balance between lithography process window and post-etch inter-layer coverage margin.

  7. Metacontrast masking is processed before grapheme-color synesthesia.

    PubMed

    Bacon, Michael Patrick; Bridgeman, Bruce; Ramachandran, Vilayanur S

    2013-01-01

    We investigated the physiological mechanism of grapheme-color synesthesia using metacontrast masking. A metacontrast target is rendered invisible by a mask that is delayed by about 60 ms; the target and mask do not overlap in space or time. Little masking occurs, however, if the target and mask are simultaneous. This effect must be cortical, because it can be obtained dichoptically. To compare the data for synesthetes and controls, we developed a metacontrast design in which nonsynesthete controls showed weaker dichromatic masking (i.e., the target and mask were in different colors) than monochromatic masking. We accomplished this with an equiluminant target, mask, and background for each observer. If synesthetic color affected metacontrast, synesthetes should show monochromatic masking more similar to the weak dichromatic masking among controls, because synesthetes could add their synesthetic color to the monochromatic condition. The target-mask pairs used for each synesthete were graphemes that elicited strong synesthetic colors. We found stronger monochromatic than dichromatic U-shaped metacontrast for both synesthetes and controls, with optimal masking at an asynchrony of 66 ms. The difference in performance between the monochromatic and dichromatic conditions in the synesthetes indicates that synesthesia occurs at a later processing stage than does metacontrast masking.

  8. Emissions and Noise Pervasive Panel

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda; Lee, Chi

    2008-01-01

    Objectives include: Provide interagency coordination of technology development, aimed at engine noise reduction. a) Provide recommendations to the Steering Committee on potential areas of interagency technology collaboration to maximize the use of government investments in noise reduction. b) Serve as a forum for information and technology exchange in order to coordinate gas turbine engine environmental strategies and policies among the member agencies and industry; c) Coordinate activities across panel representatives; and d) Communicate progress to VAATE steering committee.

  9. Effect of Attitudinal, Situational and Demographic Factors on Annoyance Due to Environmental Vibration and Noise from Construction of a Light Rapid Transit System

    PubMed Central

    Wong-McSweeney, Daniel; Woodcock, James; Waddington, David; Peris, Eulalia; Koziel, Zbigniew; Moorhouse, Andy; Redel-Macías, María Dolores

    2016-01-01

    The aim of this paper is to determine what non-exposure factors influence the relationship between vibration and noise exposure from the construction of a Light Rapid Transit (LRT) system and the annoyance of nearby residents. Noise and vibration from construction sites are known to annoy residents, with annoyance increasing as a function of the magnitude of the vibration and noise. There is not a strong correlation between exposure and levels of annoyance suggesting that factors not directly related to the exposure may have an influence. A range of attitudinal, situational and demographic factors are investigated with the aim of understanding the wide variation in annoyance for a given vibration exposure. A face-to-face survey of residents (n = 350) near three sites of LRT construction was conducted, and responses were compared to semi-empirical estimates of the internal vibration within the buildings. It was found that annoyance responses due to vibration were strongly influenced by two attitudinal variables, concern about property damage and sensitivity to vibration. Age, ownership of the property and the visibility of the construction site were also important factors. Gender, time at home and expectation of future levels of vibration had much less influence. Due to the measurement methods used, it was not possible to separate out the effects of noise and vibration on annoyance; as such, this paper focusses on annoyance due to vibration exposure. This work concludes that for the most cost-effective reduction of the impact of construction vibration and noise on the annoyance felt by a community, policies should consider attitudinal factors. PMID:27983662

  10. Effect of Attitudinal, Situational and Demographic Factors on Annoyance Due to Environmental Vibration and Noise from Construction of a Light Rapid Transit System.

    PubMed

    Wong-McSweeney, Daniel; Woodcock, James; Waddington, David; Peris, Eulalia; Koziel, Zbigniew; Moorhouse, Andy; Redel-Macías, María Dolores

    2016-12-14

    The aim of this paper is to determine what non-exposure factors influence the relationship between vibration and noise exposure from the construction of a Light Rapid Transit (LRT) system and the annoyance of nearby residents. Noise and vibration from construction sites are known to annoy residents, with annoyance increasing as a function of the magnitude of the vibration and noise. There is not a strong correlation between exposure and levels of annoyance suggesting that factors not directly related to the exposure may have an influence. A range of attitudinal, situational and demographic factors are investigated with the aim of understanding the wide variation in annoyance for a given vibration exposure. A face-to-face survey of residents (n = 350) near three sites of LRT construction was conducted, and responses were compared to semi-empirical estimates of the internal vibration within the buildings. It was found that annoyance responses due to vibration were strongly influenced by two attitudinal variables, concern about property damage and sensitivity to vibration. Age, ownership of the property and the visibility of the construction site were also important factors. Gender, time at home and expectation of future levels of vibration had much less influence. Due to the measurement methods used, it was not possible to separate out the effects of noise and vibration on annoyance; as such, this paper focusses on annoyance due to vibration exposure. This work concludes that for the most cost-effective reduction of the impact of construction vibration and noise on the annoyance felt by a community, policies should consider attitudinal factors.

  11. A phase-image watermarking scheme in gyrator domain using devil's vortex Fresnel lens as a phase mask

    NASA Astrophysics Data System (ADS)

    Yadav, A. K.; Vashisth, Sunanda; Singh, Hukum; Singh, Kehar

    2015-06-01

    We propose a watermarking scheme for phase images, based on the use of devil's vortex Fresnel lens (DVFL) as a phase mask. The DVFL provides much-desired parameter-rich phase masks which contribute to the enhanced security of the scheme in addition to overcoming the problem of axis alignment in the optical setup. The scheme uses gyrator transform (GT) in the input and the frequency domains to encrypt the input phase image before combining it with a host image. The scheme is validated for its efficacy, and analyzed for its sensitivity to various encryption parameters. Finally, it is examined for its robustness against occlusion and noise attacks.

  12. Effects of Attack and Uncontrollable Noise on Aggression

    ERIC Educational Resources Information Center

    Geen, Russell G.

    1978-01-01

    The past decade has been marked by mounting public concern over noise as a source of environmental pollution. Simultaneously, research has shown that noise is also a potent cause of physiological stress. This research relates noise to aggression concluding that noise facilitates aggression in subjects who have been instigated to aggress to the…

  13. Carbon contamination topography analysis of EUV masks

    SciTech Connect

    Fan, Y.-J.; Yankulin, L.; Thomas, P.; Mbanaso, C.; Antohe, A.; Garg, R.; Wang, Y.; Murray, T.; Wuest, A.; Goodwin, F.; Huh, S.; Cordes, A.; Naulleau, P.; Goldberg, K. A.; Mochi, I.; Gullikson, E.; Denbeaux, G.

    2010-03-12

    The impact of carbon contamination on extreme ultraviolet (EUV) masks is significant due to throughput loss and potential effects on imaging performance. Current carbon contamination research primarily focuses on the lifetime of the multilayer surfaces, determined by reflectivity loss and reduced throughput in EUV exposure tools. However, contamination on patterned EUV masks can cause additional effects on absorbing features and the printed images, as well as impacting the efficiency of cleaning process. In this work, several different techniques were used to determine possible contamination topography. Lithographic simulations were also performed and the results compared with the experimental data.

  14. Free electron laser with masked chicane

    DOEpatents

    Nguyen, Dinh C.; Carlsten, Bruce E.

    1999-01-01

    A free electron laser (FEL) is provided with an accelerator for outputting electron beam pulses; a buncher for modulating each one of the electron beam pulses to form each pulse into longitudinally dispersed bunches of electrons; and a wiggler for generating coherent light from the longitudinally dispersed bunches of electrons. The electron beam buncher is a chicane having a mask for physically modulating the electron beam pulses to form a series of electron beam bunches for input to the wiggler. In a preferred embodiment, the mask is located in the chicane at a position where each electron beam pulse has a maximum dispersion.

  15. Spatial and Temporal Visual Masking and Visibility.

    DTIC Science & Technology

    1984-10-01

    the 2AFC task. Harmonically Pure Stimuli and the Method of Adjustment The evidence presented so far supports our two-criterion 0 hypothesis for masking...the subject can still recognize this repetitive beat pattern. Figure 7 sh3ws 2AFC thresholds in the presence of a 2 c/deg mask for several tests...at all 4 rr 1.2- 1.0 W S08 N."- 0.6 b L0 12 14 16 REPLICATIONS Figlure 4 ilope of the 2AFC mssinq function with a continuall coanginq ai$& 1solid lines

  16. Robust source and mask optimization compensating for mask topography effects in computational lithography.

    PubMed

    Li, Jia; Lam, Edmund Y

    2014-04-21

    Mask topography effects need to be taken into consideration for a more accurate solution of source mask optimization (SMO) in advanced optical lithography. However, rigorous 3D mask models generally involve intensive computation and conventional SMO fails to manipulate the mask-induced undesired phase errors that degrade the usable depth of focus (uDOF) and process yield. In this work, an optimization approach incorporating pupil wavefront aberrations into SMO procedure is developed as an alternative to maximize the uDOF. We first design the pupil wavefront function by adding primary and secondary spherical aberrations through the coefficients of the Zernike polynomials, and then apply the conjugate gradient method to achieve an optimal source-mask pair under the condition of aberrated pupil. We also use a statistical model to determine the Zernike coefficients for the phase control and adjustment. Rigorous simulations of thick masks show that this approach provides compensation for mask topography effects by improving the pattern fidelity and increasing uDOF.

  17. Compensation of overlay errors due to mask bending and non-flatness for EUV masks

    NASA Astrophysics Data System (ADS)

    Chandhok, Manish; Goyal, Sanjay; Carson, Steven; Park, Seh-Jin; Zhang, Guojing; Myers, Alan M.; Leeson, Michael L.; Kamna, Marilyn; Martinez, Fabian C.; Stivers, Alan R.; Lorusso, Gian F.; Hermans, Jan; Hendrickx, Eric; Govindjee, Sanjay; Brandstetter, Gerd; Laursen, Tod

    2009-03-01

    EUV blank non-flatness results in both out of plane distortion (OPD) and in-plane distortion (IPD) [3-5]. Even for extremely flat masks (~50 nm peak to valley (PV)), the overlay error is estimated to be greater than the allocation in the overlay budget. In addition, due to multilayer and other thin film induced stresses, EUV masks have severe bow (~1 um PV). Since there is no electrostatic chuck to flatten the mask during the e-beam write step, EUV masks are written in a bent state that can result in ~15 nm of overlay error. In this article we present the use of physically-based models of mask bending and non-flatness induced overlay errors, to compensate for pattern placement of EUV masks during the e-beam write step in a process we refer to as E-beam Writer based Overlay error Correction (EWOC). This work could result in less restrictive tolerances for the mask blank non-flatness specs which in turn would result in less blank defects.

  18. Extinction controlled adaptive mask coronagraph Lyot and phase mask dual concept for wide extinction area

    NASA Astrophysics Data System (ADS)

    Bourget, P.; Schuhler, N.; Mawet, D.; Haguenauer, P.; Girard, J.; Gonte, Frederic

    2012-09-01

    A dual coronagraph based on the Adaptive Mask concept is presented in this paper. ALyot coronagraph with a variable diameter occulting disk anda nulling stellar coronagraph based on the Adaptive Phase Mask concept using polarization interferometry are presented in this work. Observations on sky and numerical simulations show the usefulness of the proposed method to optimize the nulling efficiency of the coronagraphs. In the case of the phase mask, the active control system will correct for the detrimental effects of image instabilities on the destructive interference (low-order aberrations such as tip-tilt and focus). The phase mask adaptability both in size, phase and amplitude also compensate for manufacturing errors of the mask itself, and potentially for chromatic effects. Liquid-crystal properties are used to provide variable transmission of an annulus around the phase mask, but also to achieve the achromatic π phase shift in the core of the PSF by rotating the polarization by 180°.A compressed mercury (Hg) drop is used as an occulting disk for the Lyot mask, its size control offers an adaptation to the seeing conditions and provides an optimization of the Tip-tilt correction.

  19. Advances in mask fabrication and alignment for masked ion-beam lithography

    NASA Astrophysics Data System (ADS)

    Stumbo, David P.; Damm, George A.; Engler, D. W.; Fong, F. O.; Sen, S.; Wolfe, John C.; Randall, John N.; Mauger, Phillip E.; Shimkunas, Alex R.; Loeschne, Hans

    1990-05-01

    This paper describes recent developments in three areas ofmasked ion beam lithography (MIBL). These are 1) fabrication oflarge area, low distortion, silicon stencilmasks for demagnifying ion projection lithography, 2) fabrication ofstencil masks with nanometer scale resolution for 1:1 proximity printing, and 3) development of a direct method of alignment using the ion beam induced fluorescence of Si02. These topics are discussed below. Demagnifying ion projection masks: We describe the fabrication of stencil masks in large area, low stress (10 MPa), n-type silicon membranes. The projection masks have a silicon foil area 95 mm in diameter, thicknesses between 1.5-5 and resolution of0.6um. Measured distortion (3a) in the IPL masks ranges between 0.23gm and 0.65,um, with an experimental error of 0.20 1um. Proximity printing masks: A process is described for fabricating stencil masks with 50 nm resolution in low stress, n-type silicon membranes. Membranes less than 0.5 ,ttm thick are shown to be free of the sidewall taper that limits resolution in thicker masks. These thin membranes show a slightly flared profile due to the imperfectly collimated etching ions. Alignment: A direct method of alignment is being developed which uses the ion beam induced fluorescence of Si02 marks. Fluorescence yield is characterized as a function of ion energy and resist coating thickness. The yield for Si02 is in the range between 0.1-1.0 photons/proton, while the yields for Si, Al, and photoresist are negligibly small. Thus, a simple alignment technique can be implemented where registration of a grating in the mask with a corresponding oxide pattern is detected as a fluorescence maximum. A simple model predicts that 50 nm alignment can be accomplished, following a 1 im prealignment, in 2 seconds.

  20. Cosmic Ballet or Devil's Mask?

    NASA Astrophysics Data System (ADS)

    2004-04-01

    Stars like our Sun are members of galaxies, and most galaxies are themselves members of clusters of galaxies. In these, they move around among each other in a mostly slow and graceful ballet. But every now and then, two or more of the members may get too close for comfort - the movements become hectic, sometimes indeed dramatic, as when galaxies end up colliding. ESO PR Photo 12/04 shows an example of such a cosmic tango. This is the superb triple system NGC 6769-71, located in the southern Pavo constellation (the Peacock) at a distance of 190 million light-years. This composite image was obtained on April 1, 2004, the day of the Fifth Anniversary of ESO's Very Large Telescope (VLT). It was taken in the imaging mode of the VIsible Multi-Object Spectrograph (VIMOS) on Melipal, one of the four 8.2-m Unit Telescopes of the VLT at the Paranal Observatory (Chile). The two upper galaxies, NGC 6769 (upper right) and NGC 6770 (upper left), are of equal brightness and size, while NGC 6771 (below) is about half as bright and slightly smaller. All three galaxies possess a central bulge of similar brightness. They consist of elderly, reddish stars and that of NGC 6771 is remarkable for its "boxy" shape, a rare occurrence among galaxies. Gravitational interaction in a small galaxy group NGC 6769 is a spiral galaxy with very tightly wound spiral arms, while NGC 6770 has two major spiral arms, one of which is rather straight and points towards the outer disc of NGC 6769. NGC 6770 is also peculiar in that it presents two comparatively straight dark lanes and a fainter arc that curves towards the third galaxy, NGC 6771 (below). It is also obvious from this new VLT photo that stars and gas have been stripped off NGC 6769 and NGC 6770, starting to form a common envelope around them, in the shape of a Devil's Mask. There is also a weak hint of a tenuous bridge between NGC 6769 and NGC 6771. All of these features testify to strong gravitational interaction between the three galaxies