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Journal of the Acoustical Society of America

Grigory I Dolgikh, Sergey S Budrin, Stanislav G Dolgikh, Vladimir V Ovcharenko, Vladimir A Chupin, Sergey V Yakovenko
The paper analyzes the experimental data obtained in a comprehensive experiment aimed at identifying the regularities of transmitted hydroacoustic signal transformations at the shelf of decreasing depth. The 33 Hz harmonic hydroacoustic signals were generated at the shelf of the Sea of Japan by a low-frequency source. Distribution of the transmitted energy at vertical sounding from the surface to the bottom was studied at different shelf points with Bruel & Kjaer 8104 hydrophone. At the shore, the transformed seismo-acoustic signals were received by a 52...
October 2017: Journal of the Acoustical Society of America
Catherine D de Groot-Hedlin
Numerical computations of the Navier-Stokes equations governing acoustic propagation are performed to investigate infrasound propagation in the troposphere and into acoustic shadow zones. An existing nonlinear finite-difference, time-domain (FDTD) solver that constrains input sound speed models to be axisymmetric is expanded to allow for advection and rigid, stair-step topography. The FDTD solver permits realistic computations along a given azimuth. It is applied to several environmental models to examine the effects of nonlinearity, topography, advection, and two-dimensional (2D) variations in wind and sound speeds on the penetration of infrasound into shadow zones...
October 2017: Journal of the Acoustical Society of America
M Niskanen, J-P Groby, A Duclos, O Dazel, J C Le Roux, N Poulain, T Huttunen, T Lähivaara
A method to characterize macroscopically homogeneous rigid frame porous media from impedance tube measurements by deterministic and statistical inversion is presented. Equivalent density and bulk modulus of the samples are reconstructed with the scattering matrix formalism, and are then linked to its physical parameters via the Johnson-Champoux-Allard-Lafarge model. The model includes six parameters, namely the porosity, tortuosity, viscous and characteristic lengths, and static flow and thermal permeabilities...
October 2017: Journal of the Acoustical Society of America
Eric Rokni, Lauren M Neldner, Camille Adkison, Thomas R Moore
Phantom partials are anomalous overtones in the spectrum of the piano sound that occur at sum and difference frequencies of the natural overtones of the string. Although they are commonly assumed to be produced by forced longitudinal waves in the string, analysis of the sound of a piano produced by mechanically vibrating the soundboard while all the strings are damped indicates that phantom partials can occur in the absence of string motion. The magnitude of the effect leads to the conclusion that nonlinearity in the non-string components may be responsible for some of the power in the phantom partials...
October 2017: Journal of the Acoustical Society of America
Matthias K Franken, Daniel J Acheson, James M McQueen, Frank Eisner, Peter Hagoort
An important part of understanding speech motor control consists of capturing the interaction between speech production and speech perception. This study tests a prediction of theoretical frameworks that have tried to account for these interactions: If speech production targets are specified in auditory terms, individuals with better auditory acuity should have more precise speech targets, evidenced by decreased within-phoneme variability and increased between-phoneme distance. A study was carried out consisting of perception and production tasks in counterbalanced order...
October 2017: Journal of the Acoustical Society of America
Mickael L D Deroche, Charles J Limb, Monita Chatterjee, Vincent L Gracco
Musicians can sometimes achieve better speech recognition in noisy backgrounds than non-musicians, a phenomenon referred to as the "musician advantage effect." In addition, musicians are known to possess a finer sense of pitch than non-musicians. The present study examined the hypothesis that the latter fact could explain the former. Four experiments measured speech reception threshold for a target voice against speech or non-speech maskers. Although differences in fundamental frequency (ΔF0s) were shown to be beneficial even when presented to opposite ears (experiment 1), the authors' attempt to maximize their use by directing the listener's attention to the target F0 led to unexpected impairments (experiment 2) and the authors' attempt to hinder their use by generating uncertainty about the competing F0s led to practically negligible effects (experiments 3 and 4)...
October 2017: Journal of the Acoustical Society of America
Stephen T Neely, Daniel M Rasetshwane
The level-dependent component of the latency of human auditory brainstem responses (ABR) to tonebursts decreases by about 38% for every 20-dB increase in stimulus level over a wide range of both frequency and level [Neely, Norton, Gorga, and Jesteadt (1998). J. Acoust. Soc. Am. 31, 87-97]. This level-dependence has now been simulated in an active, nonlinear, transmission-line model of cochlear mechanics combined with an adaptation stage. The micromechanics in this model are similar to previous models except that a dual role is proposed for the tectorial membrane (TM): (1) passive sharpening the tuning of sensory-cell inputs (relative to basilar-membrane vibrations) and (2) providing an optimal phase shift (relative to basilar-membrane vibrations) of outer-hair-cell feedback forces, so that amplification is restricted to a limited range of frequencies...
October 2017: Journal of the Acoustical Society of America
Ronald A Kastelein, Lean Helder-Hoek, Shirley Van de Voorde, Alexander M von Benda-Beckmann, Frans-Peter A Lam, Erwin Jansen, Christ A F de Jong, Michael A Ainslie
In seismic surveys, reflected sounds from airguns are used under water to detect gas and oil below the sea floor. The airguns produce broadband high-amplitude impulsive sounds, which may cause temporary or permanent threshold shifts (TTS or PTS) in cetaceans. The magnitude of the threshold shifts and the hearing frequencies at which they occur depend on factors such as the received cumulative sound exposure level (SELcum), the number of exposures, and the frequency content of the sounds. To quantify TTS caused by airgun exposure and the subsequent hearing recovery, the hearing of a harbor porpoise was tested by means of a psychophysical technique...
October 2017: Journal of the Acoustical Society of America
Cornelis Weemstra, Kees Wapenaar, Karel N van Dalen
In an acoustical context, interferometry takes advantage of existing (ambient) wavefield recordings by turning receivers into so-called "virtual sources." The medium's response to these virtual sources can be harnessed to image that medium. Most interferometric applications, however, suffer from the fact that the retrieved virtual-source responses deviate from the true medium responses. The accrued artefacts are often predominantly due to a non-isotropic illumination of the medium of interest, and prohibit accurate interferometric imaging...
October 2017: Journal of the Acoustical Society of America
Sipei Zhao, Matthew Dabin, Eva Cheng, Xiaojun Qiu, Ian Burnett, Jacob Chia-Chun Liu
This paper investigates the wind noise reduction mechanism of porous microphone windscreens. The pressure fluctuations inside the porous windscreens with various viscous and inertial coefficients are studied with numerical simulations. The viscous and inertial coefficients represent the viscous forces resulting from the fluid-solid interaction along the surface of the pores and the inertial forces imposed on the fluid flow by the solid structure of the porous medium, respectively. Simulation results indicate that the wind noise reduction first increases and then decreases with both viscous and inertial coefficients after reaching a maximum...
October 2017: Journal of the Acoustical Society of America
Eric B Whiting, Joseph S Lawrence, Kent L Gee, Tracianne B Neilsen, Scott D Sommerfeldt
Sound intensity measurements using two microphones have traditionally been processed using a cross-spectral method with inherent error in the finite-sum and finite-difference formulas. The phase and amplitude gradient estimator method (PAGE) has been seen experimentally to extend the bandwidth of broadband active intensity estimates by an order of magnitude. To provide an analytical foundation for the method, bias errors in active intensity and specific acoustic impedance are presented and compared to those of the traditional method...
October 2017: Journal of the Acoustical Society of America
Zhongchang Song, Yu Zhang, Steven W Thornton, Songhai Li, Jianchen Dong
The wave propagation, sound field, and transmission beam pattern of a pygmy sperm whale (Kogia breviceps) were investigated in both the horizontal and vertical planes. Results suggested that the signals obtained at both planes were similarly characterized with a high peak frequency and a relatively narrow bandwidth, close to the ones recorded from live animals. The sound beam measured outside the head in the vertical plane was narrower than that of the horizontal one. Cases with different combinations of air-filled structures in both planes were used to study the respective roles in controlling wave propagation and beam formation...
October 2017: Journal of the Acoustical Society of America
P F Joseph
This paper describes a measurement technique that allows the modal amplitude distribution to be determined in ducts with mean flow and reflections. The method is based only on measurements of the acoustic pressure two-point coherence at the duct wall. The technique is primarily applicable to broadband sound fields in the high frequency limit and whose mode amplitudes are mutually incoherent. The central assumption underlying the technique is that the relative mode amplitude distribution is independent of frequency...
October 2017: Journal of the Acoustical Society of America
Georgia Zellou
Surface-level phonetic details are used during word recognition. Yet, questions remain about how these details are encoded in lexical representations and the role of memory and attention during this process. The current study utilizes lexical repetition priming to examine the effect of a delay between hearing a word repeated with either the same or different coarticulatory patterns on lexical recognition. Listeners were faster to recognize repeated words with the same patterns of coarticulatory nasality, confirming that subphonemic information is encoded in the lexicon...
October 2017: Journal of the Acoustical Society of America
Donna Erickson
No abstract text is available yet for this article.
October 2017: Journal of the Acoustical Society of America
Nicole Wayant, Edward T Nykaza
Dose-response curves lie at the heart of most global community noise laws/policies. Yet, there is no standard on how to choose the noise dose bins that underlie the curves which describe the relationship between noise and annoyance. This paper strives to understand whether the binning process affects the modeled relationship by examining common binning and curve-fitting procedures. It was found that the subjective choice of bin-width can considerably affect the resulting dose-response curves. The implications of these findings are discussed and recommendations are given to ameliorate the situation so that future studies and policies can avoid these potential pitfalls...
October 2017: Journal of the Acoustical Society of America
Zhongchang Song, Yu Zhang, Xianyan Wang, Chong Wei
A finite element method was used to investigate the temperature influence on sound beams of the Indo-Pacific humpback dolphin. The numerical models of a dolphin, which originated from previous computed tomography (CT) scanning and physical measurement results, were used to investigate sound beam patterns of the dolphin in temperatures from 21 °C to 39 °C, in increments of 2 °C. The -3 dB beam widths across the temperatures ranged from 9.3° to 12.6°, and main beam angle ranged from 4.7° to 7.2° for these temperatures...
October 2017: Journal of the Acoustical Society of America
Lei Xiong, Benoit Nennig, Yves Aurégan, Wenping Bi
A metamaterial composed of a set of periodic rigid resonant inclusions embedded in a porous lining is investigated to enhance the sound attenuation in an acoustic duct at low frequencies. A transmission loss peak is observed on the measurements and corresponds to the crossing of the lower two Bloch modes of an infinite periodic material. Numerical parametric studies show that the optimum modal attenuation can be achieved at the exceptional point in the parameter plane of inclusion position and frequency, where the two lower modes merge...
October 2017: Journal of the Acoustical Society of America
Jakob Tougaard, Michael Dähne
A key question related to regulating noise from pile driving, air guns, and sonars is how to take into account the hearing abilities of different animals by means of auditory frequency weighting. Recordings of pile driving sounds, both in the presence and absence of a bubble curtain, were evaluated against recent thresholds for temporary threshold shift (TTS) for harbor porpoises by means of four different weighting functions. The assessed effectivity, expressed as time until TTS, depended strongly on choice of weighting function: 2 orders of magnitude larger for an audiogram-weighted TTS criterion relative to an unweighted criterion, highlighting the importance of selecting the right frequency weighting...
October 2017: Journal of the Acoustical Society of America
Brian K Branstetter, Kaitlin R Van Alstyne, Teri A Wu, Rachel A Simmons, Lara D Curtis, Mark J Xitco
Critical ratios (CRs) are useful for estimating detection thresholds of tonal signals when the spectral density of noise is known. In cetaceans, CRs have only been measured for a few animals representing four odontocete species. These data are sparse, particularly for lower frequencies where anthropogenic noise is concentrated. There is currently no systematic method for implementing CR predictions (e.g., a composite frequency-dependent CR function). The current study measures CRs for two bottlenose dolphins (Tursiops truncatus) and estimates composite CR functions...
October 2017: Journal of the Acoustical Society of America
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