A miniature differential microphone is described that has a noise floor that is substantially lower than that of existing devices of comparable size. The sensitivity of a differential microphone suffers as the distance between the two pressure sensing locations decreases, resulting in an increase in the input sound pressure-referred noise ...

The correct assessment of impulse noise from occupational environments for hearing-conservation purposes is still a controversial issue. Currently, no universally accepted standard defines impulse noise accurately nor does a standard method exist to measure impulses. Moreover, current impulse-damage risk-criteria suffer from lack of empirical data needed to quantify impulse noise ...

During the late 1970s and early 1980s, careful measurements of ambient noise were made in the Tongue of the Ocean (TOTO) in the Bahamas. The measurements were made using a vertical array of five omni-directional hydrophones moored in 2200 m water depth with an average hydrophone depth of 122 m. ...

It is of common knowledge, and well documented, that laboratory-measured noise attenuation values of most hearing protection devices (HPD) exceed significantly the attenuation values obtained in real-world workplace environments. Various reasons may explain such discrepancies (lack of training, wearing time, lack of comfort, bad fitting, noise environments, etc.) but very ...

The acoustical ergonomic is an important target for any room acoustics, intelligibility and community noise. The authors explain the experience on metrological and neuropsychological approach to the human reaction to noise. Environmental sound quality, room acoustics and interference of perceived sound (interference with the privacy) can start subjective effects and ...

The absence of audible noise in recording studios is highly desirable. For this reason, the acoustic design of recording facilities usually involves an accurate assessment of the audibility of background noise. However, noise criterion that sets levels for inaudible noise do not take in account the sensitivity of today's digital ...

This paper presents the tri-dimensional acoustical characterization of Castelo Branco Hospital. Traffic and air conditioning machines produce noise that influences the Hospital and the buildings nearby. The results are presented in two dimensions at a height of four meters above the ground and in the vertical direction to access the ...

Numerous low frequency transient signals arriving from Antarctica have been detected in five-year sea noise recordings in 2002-2006 at the hydroacoustic listening station deployed off Cape Leeuwin in Western Australia as part of the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty. The majority of these signals consist of a ...

Recently, several attempts to use speed bumps as a noise reduction method have been made. Objective analyses of the effect of speed bumps on noise have been shown to result in a rather small reduction of noise. In the present paper the influence of speed bumps on perceived annoyance is ...

The major source of environmental noise exposure is road traffic noise. Of all noise sources, tyre rolling noise is dominant for speeds above 30 kmh for passenger cars. Tyre rolling noise can be subdivided into interior and exterior noise. For the interior noise to which the passengers are exposed to, ...

The Nantucket Airport in Massachusetts serves primarily turboprop commuter aircraft, and private or charter jets, with most of its operations in the summer. A seasonal homeowner was severely affected by arrival flight noise and requested noise measurements and noise control recommendations for this architect-designed residence. Time was spent with the ...

We present a preliminary study of the dependence of the statistical features of the soil motion due to seismic noise on the near-surface geology in the frequency range from 1 Hz to ~ 40 Hz. In detail, we have investigated the 3D average squared soil displacement ⟨r2⟩ and the distribution ...

Cross-modal facilitation of response time (RT) is said to occur in a selective attention task when the introduction of an irrelevant sound increases the speed at which visual stimuli are detected and identified. To investigate the source of the facilitation in RT, we asked participants to rapidly identify the color ...

The perceived strength of intensity fluctuations evoked by suprathreshold sinusoidal amplitude modulation (AM) and the perceived size of intensity increments were compared across levels of a wideband noise and a 1-kHz tone. For the 1-kHz tone, the comparisons were made in quiet and in a high-pass noise. The data indicate ...

The benefits of combined electric and acoustic stimulation (EAS) in terms of speech recognition in noise are well established; however the underlying factors responsible for this benefit are not clear. The present study tests the hypothesis that having access to acoustic information in the low frequencies makes it easier for ...

Noise of machines in various agro-based industries was found to be the major occupational hazard for the workers of industries. The predominant noise sources need to be identified and the causes of high noise need to be studied to undertake the appropriate measures to reduce the noise level in one ...

It has recently been shown that noise can facilitate signal detection in the sensory systems. We have previously shown that contrast detection sensitivity in the visual perception is improved in the presence of noise by measuring the detection threshold (Sasaki et al. Effect of noise on the contrast detection threshold ...

Overshoot, the elevation in the threshold for a brief signal that comes on close to masker onset, was measured with signal frequency certain (same frequency on every trial) or uncertain (randomized over trials). In broadband noise, thresholds were higher 2 ms after masker onset than 200 ms later, by 9 ...

Inverted and contrast-reversed faces are identified less accurately and less rapidly than normal, upright faces. The effects of inversion and contrast-reversal may reflect different sampling strategies and/or different levels of internal noise. To test these alternative hypotheses, we used a combination of noise-masking and response-consistency techniques to measure the internal ...

Vocal structure can vary between populations due to variation in ecology-dependent selection pressures, such as masking by background noise and the presence of eavesdroppers. Signalers can overcome these obstacles to effective communication by avoiding frequencies that overlap with background noise or the audible range of eavesdroppers. In the Northeastern Pacific ...

The purpose of this retrospective study is to examine the possible association between iris pigmentation and susceptibility to noise-induced hearing loss in 2407 noise-exposed workers. The workers were between 16 to 65 years of age and were exposed to 2 to 42 years of work-related noise. Results demonstrated that dark-eyed ...

The present study used 1/f noise to examine how spatial, physical, and timing constraints affect planning and control processes in aiming. Participants moved objects of different masses to different distances at preferred speed (Experiment 1) and as quickly as possible (Experiment 2). Power spectral density, standardized dispersion, rescaled range, and ...

Recent loudness data of single noise bursts indicate that spectral loudness summation depends on signal duration. To gain insight into the mechanisms underlying this duration effect, loudness was measured as a function of signal bandwidth centered around 2 kHz for sequences of 10-ms noise bursts at various repetition rates and, ...

BACKGROUND: The authors investigated the suitability of different electroencephalographic parameters to quantify the anesthetic effect of desflurane, isoflurane, and sevoflurane in rats. METHODS: Ten male Sprague-Dawley rats were anesthetized in a randomized crossover design with maximum values of 11% desflurane, 2.1% isoflurane, and 3.5% sevoflurane. The electroencephalogram was recorded with ...

With conventional light microscopy, precision in the measurement of the displacement of a specimen depends on the signal-to-noise ratio when we measure the light intensity of magnified images. This implies that, for the improvement of precision, getting brighter images and reducing background light noise are both inevitably required. For this ...

PURPOSE: The Lombard effect describes the tendency for speakers to increase pitch, intensity, and duration in the presence of noise. It is unclear whether these modifications are uniformly applied across all words within an utterance or whether information-bearing content words are further enhanced compared with function words. In the present ...

Information about sensory stimuli is represented by spatiotemporal patterns of neural activity. The complexity of the central nervous system, however, frequently obscures the origin and properties of signals and noise that underlie these activity patterns. We minimized this constraint by examining mechanisms governing correlated activity in mouse retinal ganglion cells ...

We study ionic current fluctuations in solid-state nanopores over a wide frequency range and present a complete description of the noise characteristics. At low frequencies (f approximately < 100 Hz) we observe 1/f-type of noise. We analyze this low-frequency noise at different salt concentrations and find that the noise power ...

There is no consensus on the type of nonlinearity enabling motion processing of second-order stimuli. Some authors suggest that a nonlinearity specifically applied to second-order stimuli prior to motion processing (e.g., rectification process) recovers the spatial structure of the signal permitting subsequent first-order motion analyses (e.g., filter-rectify-filter model). Others suggest ...

The purposes of this study were to: (1) compare medial olivocochlear system (MOCS) functioning and speech perception in noise in young and older adults and (2) to quantify the correlation between MOCS functioning and speech perception in noise. Measurements were taken in 20 young (mean 26.3 +/- 2.1 years) and ...

OBJECTIVES: The aim of this study was to evaluate hearing in a population of industrial workers exposed to occupational noise by using both conventional and extended high-frequency (EHF) audiometry, and to compare our results with the findings from a control group. METHODS: A total of 139 industry workers exposed to ...

Amblyopia results in a loss of visual acuity, contrast sensitivity, and position acuity. However, the nature of the neural losses is not yet fully understood. Here we report the results of experiments using noise to try to better understand the losses in amblyopia. Specifically, in one experiment we compared the ...

Artificial scotomas positioned within peripheral dynamic noise fade perceptually during visual fixation (that is, the surrounding dynamic noise appears to fill-in the scotoma). Because the scotomas' edges are continuously refreshed by the dynamic noise background, this filling-in effect cannot be explained by low-level adaptation mechanisms (such as those that may ...

BACKGROUND: Stochastic resonance is a nonlinear phenomenon whereby the addition of noise can improve the detection of weak stimuli. An optimal amount of added noise results in the maximum enhancement, whereas further increases in noise intensity only degrade detection or information content. The phenomenon does not occur in linear systems, ...

Noise level monitoring and its reduction with different width and height of vegetation belt were studied in the Varanasi city. Noise level monitoring of the Varanasi city revealed the fact that area category A (without vegetation) was highly polluted as compare to area category B (with vegetation) having less fluctuation ...

A correlated random telegraph signal is observed from the interaction of two individual defects in a carbon nanotube transistor. It is shown that the amplitude fluctuation of one defect significantly depends on the state of the other defect. Moreover, statistics of the correlated switchings is shown to deviate from the ...

We have demonstrated error-free operations of slow-light via stimulated Brillouin scattering (SBS) in optical fiber for 10-Gb/s signals with different modulation formats, including non-return-to-zero (NRZ), phase-shaped binary transmission (PSBT) and differential phase-shiftkeying (DPSK). The SBS gain bandwidth is broadened by using current noise modulation of the pump laser diode. The ...

The distinguishing spatial properties of low-frequency microphone wind noise (turbulent pressure disturbances) are examined with a planar, 49-element array. Individual, propagating transient pressure disturbances are imaged by wavelet processing to the array data. Within a given frequency range, the wind disturbances are much smaller and less spatially coherent than sound ...

The impact of anthropogenic noise on marine mammals has been an area of increasing concern over the past two decades. Most low-frequency anthropogenic noise in the ocean comes from commercial shipping which has contributed to an increase in ocean background noise over the past 150 years. The long-term impacts of ...

Neurons are notoriously noisy devices. Although the traditional view posits that noise degrades system performance, recent evidence suggests that noise may instead enhance neural information processing under certain conditions. Here we report that random channel and synaptic noise improve the ability of a biologically realistic computational model of the Hermissenda ...

In a companion paper we showed that random channel and synaptic noise improve the ability of a biologically realistic, GENESIS-based computational model of the Hermissenda eye to encode light intensity. In this paper we explore mechanisms for noise-induced improvement by examining contextual spike-timing relationships among neurons in the photoreceptor network. ...

Little, if any, work has explicitly addressed independence in the perception of complex sounds. General recognition theory provides a powerful framework in which to address such issues. Two experiments were carried out to test within-stimulus, between-stimulus, and decision-related notions of independence in each of two stimulus sets. One set consisted ...

Faults of rotating parts of a machine normally generate unexpected frequency band or impulsive sound, which has a period when it moves with a constant speed. The former can be detected by the moving frame acoustic holography method [S.-H. Park and Y.-H. Kim, ''An improved moving frame acoustic holography for ...

Field measurements of impact sound transmission using the ISO standard tapping machine are compared with field measurements of human walkers in both wood and concrete buildings. In wood frame construction, low-frequency noise dominates the spectrum with most floor coverings. In concrete buildings, high-frequency noise is the controlling factor in non-carpeted ...

The roles of spectro-temporal coherence, lexical status, and word position in the perception of speech in acoustic signals containing a mixture of speech and nonspeech sounds were investigated. Stimuli consisted of nine (non)words in which either white noise was inserted only into the silent interval preceding and/or following the onset ...

Anthropogenic noise is compromising the habitat for marine mammals, fish, and, potentially, other marine organisms. Determining acceptable thresholds is confounded by the fact that marine animals have adapted to some exceedingly loud naturally occurring sounds, whereas exposure to certain anthropogenic noises at equivalent or lower amplitudes causes harm. It is ...

Optical fiber infrasound sensors (OFIS) are compliant tubes wrapped with two optical fibers that integrate pressure variation along the length of the tube with laser interferometry. The coherent signals traveling at acoustic speed are averaged along the length of the OFIS at the speed of light, while spatially incoherent noise ...

Noise level measurements made in a performance hall and in related spaces with subjectively described light, moderate, and heavy rainfall on the facility roof are presented in octave frequency bands, and as described by associated A weighted sound pressure levels and noise criteria (NC) ratings. Rain noise levels are also ...

Detection theory measures of listener performance, as well as distinctive feature scoring, have been shown to provide useful additional information to percent correct scores when testing word recognition. The diagnostic rhyme test (DRT) uses a two-item multiple choice (MC) response format to provide percent correct and distinctive feature information but ...

It is stated that there is no convincing evidence that animals are deterred by intense sounds (Heffner 2007). Nevertheless, it must be thoroughly examined to what extent animals are impaired by specific environmental noise with regard to their orientation, communication, behavior, etc. Such interferences would significantly influence the animals' life. ...