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Journal of the Acoustical Society of America

Bruce G Berg, Joann Zhu, Alison Y Tan, Ewa M Borucki
Theoretically, discriminating an amplitude modulated tone (AM) from a quasi-frequency modulated tone (QFM) is an ideal task for measuring the bandwidth of phase sensitivity because the stimuli have identical amplitude spectra but different phase spectra. The stimuli are perfectly discriminable at narrow bandwidths, but become indistinguishable at wide bandwidths. Measurements, however, are thought to be compromised by auditory distortion products, particularly a cubic distortion tone which interacts with the lower sideband of the stimulus to create an intensity cue...
June 2018: Journal of the Acoustical Society of America
Yutong Xue, J Stuart Bolton
Based on the idea that a layer of properly designed and manufactured fibrous material can serve as both a sound absorber and a structural damper, an approach is introduced in this article to design the microstructure of a fibrous layer for it to provide optimal damping performance. To begin with, previous work related to structural damping by fibrous layers was reviewed. Then the most appropriate models from the literature were adapted for use in the current study. A system comprising an aluminum panel and a limp fibrous layer was driven by a line force, and both the spatial velocity response of the panel and the power distribution within the system were calculated to quantify the degree of damping provided by the fibrous layer, which helped identify the airflow resistivity that provides optimal damping for any frequency and panel of interest...
June 2018: Journal of the Acoustical Society of America
Ning Xiang, Aditya Alamuru, Ingo B Witew, Michael Vorländer
The aim of this work is to study the sound field distribution in an experimental scale-model of two coupled rooms. An automatic scanning mechanism moves a microphone in small grid steps to measure room impulse responses at each grid point. The measurements cover the entire two-dimensional area of the coupled rooms. Sound energy distributions can be analyzed in the form of animated visual displays, revealing sound propagation across the coupling aperture and inside each room. This paper describes the measurement results, and the analysis method, which offer deep insights into the temporal development of a sound field in coupled spaces...
June 2018: Journal of the Acoustical Society of America
Natalie Agus, Hans Anderson, Jer-Ming Chen, Simon Lui, Dorien Herremans
In many applications, it is desirable to achieve a signal that is as close as possible to ideal white noise. One example is in the design of an artificial reverberator, whereby there is a need for its lossless prototype output from an impulse input to be perceptually white as much as possible. The Ljung-Box test, the Drouiche test, and the Wiener Entropy-also called the Spectral Flatness Measure-are three well-known methods for quantifying the similarity of a given signal to ideal white noise. In this paper, listening tests are conducted to measure the Just Noticeable Difference (JND) on the perception of white noise, which is the JND between ideal Gaussian white noise and noise with a specified deviation from the flat spectrum...
June 2018: Journal of the Acoustical Society of America
Samuele Carcagno, Christophe Micheyl, Marion Cousineau, Daniel Pressnitzer, Laurent Demany
Using a same-different discrimination task, it has been shown that discrimination performance for sequences of complex tones varying just detectably in pitch is less dependent on sequence length (1, 2, or 4 elements) when the tones contain resolved harmonics than when they do not [Cousineau, Demany, and Pessnitzer (2009). J. Acoust. Soc. Am. 126, 3179-3187]. This effect had been attributed to the activation of automatic frequency-shift detectors (FSDs) by the shifts in resolved harmonics. The present study provides evidence against this hypothesis by showing that the sequence-processing advantage found for complex tones with resolved harmonics is not found for pure tones or other sounds supposed to activate FSDs (narrow bands of noise and wide-band noises eliciting pitch sensations due to interaural phase shifts)...
June 2018: Journal of the Acoustical Society of America
Babak Khodabandeloo, Martin Landrø
For seismic air-gun arrays, ghost cavitation is assumed to be one of the main mechanisms for high-frequency signal generation. Ghost cavitation signals are weak for seismic frequencies (<300 Hz) and do not contribute to seismic reflection profiling. In the current experiment, the ghost cavity cloud is monitored by a high-speed video camera using 120 frames per second. This is, as far as the authors know, the first convincing photographic evidence of ghost-induced cavitation. In addition to video recording, acoustic signals were recorded with a sampling rate of 312...
June 2018: Journal of the Acoustical Society of America
Rémi Emmetière, Julien Bonnel, Marie Géhant, Xavier Cristol, Thierry Chonavel
The Waveguide Invariant (WI) theory has been introduced to quantify the orientation of the intensity interference patterns in a range-frequency domain. When the sound speed is constant over the water column, the WI is a scalar with the canonical value of 1. But, when considering shallow waters with a stratified sound speed profile, the WI ceases to be constant and is more appropriately described by a distribution, which is mainly sensitive to source/receiver depths. Such configurations have been widely investigated, with practical applications including passive source localization...
June 2018: Journal of the Acoustical Society of America
Samuel A Verburg, Efren Fernandez-Grande
Capturing the impulse or frequency response functions within extended regions of a room requires an unfeasible number of measurements. In this study, a method to reconstruct the response at arbitrary points based on compressive sensing (CS) is examined. The sound field is expanded into plane waves and their amplitudes are estimated via CS, obtaining a spatially sparse representation of the sound field. The validity of the CS assumptions are discussed, namely, the assumption of the wave field spatial sparsity (which depends strongly on the properties of the specific room), and the coherence of the sensing matrix due to different spatial sampling schemes...
June 2018: Journal of the Acoustical Society of America
Lei Feng, Andrew J Oxenham
The identity of a speech sound can be affected by the long-term spectrum of a preceding stimulus. Poor spectral resolution of cochlear implants (CIs) may affect such context effects. Here, spectral contrast effects on a phoneme category boundary were investigated in CI users and normal-hearing (NH) listeners. Surprisingly, larger contrast effects were observed in CI users than in NH listeners, even when spectral resolution in NH listeners was limited via vocoder processing. The results may reflect a different weighting of spectral cues by CI users, based on poorer spectral resolution, which in turn may enhance some spectral contrast effects...
June 2018: Journal of the Acoustical Society of America
Richard L Weaver, John Y Yoritomo
The authors consider the retrieval of Green functions G from the correlations of non-stationary non-fully diffuse noise incident on an array of sensors. Multiple schemes are proposed for optimizing the time-varying weights with which correlations may be stacked. Using noise records created by direct numerical simulation of waves in a two-dimensional multiply scattering medium, cases are shown in which conventional stacking does a poor job and for which the proposed schemes substantially improve the recovered G, rendering it more causal and/or more symmetric, and more similar to the actual G...
June 2018: Journal of the Acoustical Society of America
Shoichi Koyama, Naoki Murata, Hiroshi Saruwatari
A sound field recording and reproduction method based on sparse sound field decomposition is proposed. Most current methods are based on plane-wave or harmonic decomposition of the pressure distribution obtained by microphones, which leads to spatial aliasing artifacts with severe effects. This paper proposes a method for sound field decomposition based on a generative model of the sound field consisting of near-field source components and far-field plane-wave components. Since the distribution of the near-field source components can be assumed to be spatially sparse, the pressure distribution obtained by the microphones can be decomposed into these two components using sparse decomposition algorithms...
June 2018: Journal of the Acoustical Society of America
Najwa Alghamdi, Steve Maddock, Ricard Marxer, Jon Barker, Guy J Brown
This paper presents a bi-view (front and side) audiovisual Lombard speech corpus, which is freely available for download. It contains 5400 utterances (2700 Lombard and 2700 plain reference utterances), produced by 54 talkers, with each utterance in the dataset following the same sentence format as the audiovisual "Grid" corpus [Cooke, Barker, Cunningham, and Shao (2006). J. Acoust. Soc. Am. 120(5), 2421-2424]. Analysis of this dataset confirms previous research, showing prominent acoustic, phonetic, and articulatory speech modifications in Lombard speech...
June 2018: Journal of the Acoustical Society of America
Yixin Yang, Yahao Zhang, Long Yang
Wideband direction of arrival (DOA) estimation using a sensor array plays a fundamental role in passive sonar signal processing. Although sparsity-based DOA estimation methods can attain high resolution in the condition of few snapshots and low signal-to-noise ratio, the localization accuracy is seriously affected by strong interferences. In this paper, a matrix filter with nulling (MFN) is used to pass weak targets in sector-of-interest (passband) while attenuating the out-of-sector (stopband) interferences by forming deep nulls toward the directions of interferences adaptively...
June 2018: Journal of the Acoustical Society of America
Jørgen Hald
During the past decade, several publications have described the use of compressive sensing principles to extend the frequency range supported by a given irregular microphone array for near-field acoustic holography. The applied numerical source model has typically been of the type used for the equivalent source method, i.e., a mesh of point sources, and a one-norm regularized inverse problem has been solved using a very stable, but slow interior-point optimization algorithm. A few publications have investigated the use of simpler and faster iterative algorithms...
June 2018: Journal of the Acoustical Society of America
Mingsian R Bai, Chun Chung, Shih-Syuan Lan
In this paper, an iterative Compressive Sensing (CS) algorithm is proposed for acoustical source characterization problems with block sparsity constraints. Source localization and signal separation are accomplished in a unified CS framework. The inverse problem is formulated with the Equivalent Source Method as a linear underdetermined system of equations. As conventional approaches based on convex optimization can be computationally expensive and fail to deal with continuously distributed sources, the proposed approach that is adapted from the Newton's method and is augmented with a special pruning procedure is capable of solving the inverse problem far more efficiently with comparable accuracy...
June 2018: Journal of the Acoustical Society of America
Li-Hsin Ning, Torrey M Loucks, Chilin Shih
Speakers can adjust pitch using auditory feedback through a short-latency corrective response known as the pitch-shift response (PSR). Suppression of the PSR denotes on-line stabilization of pitch. In this paper, the hypothesis that pitch-shift responses can be suppressed with real-time visual feedback of vocal F0 is investigated. Mandarin speakers and naive speakers without tonal language experience were instructed to produce the sustained vowel /a/ and Mandarin tone /ma1/ in an audio-only condition and a separate audio-visual condition...
June 2018: Journal of the Acoustical Society of America
Juan Ramirez, Jeffrey S Rogers
Co-prime array geometries have received a great deal of attention due to their ability to discriminate O(MN) sources with only O(M + N) sensors. This has been demonstrated both theoretically and in simulation. However, there are many practical limitations that make it difficult to realize the enhanced degrees of freedom when applying co-prime geometries to real acoustic data taken on a horizontal line array. For instance, co-prime sampling leads to grating lobes that can obscure lower signal-to-noise-ratio acoustic signals making them difficult to detect...
June 2018: Journal of the Acoustical Society of America
Tobias Piechowiak, Changxue Ma, Rob de Vries, Andrew Dittberner
Beamforming techniques are widely used in hearing aids to enhance the intelligibility of speech from a target direction, but they tend to isolate the listener from their acoustic environment and distort spatial cues. The main reason for this is that a typical beamformer method alters the head-related transfer function of the individual users' ears and functions under monaural assumptions instead of a binaural model. In this letter, a binaural auditory steering strategy (BASS) is proposed for the design of asymmetrically presented spatial filters which improves awareness of the surrounding acoustic environment while preserving intelligibility from a target direction...
June 2018: Journal of the Acoustical Society of America
Nawal El Boghdady, Deniz Başkent, Etienne Gaudrain
The vocal tract length (VTL) of a speaker is an important voice cue that aids speech intelligibility in multi-talker situations. However, cochlear implant (CI) users demonstrate poor VTL sensitivity. This may be partially caused by the mismatch between frequencies received by the implant and those corresponding to places of stimulation along the cochlea. This mismatch can distort formant spacing, where VTL cues are encoded. In this study, the effects of frequency mismatch and band partitioning on VTL sensitivity were investigated in normal hearing listeners with vocoder simulations of CI processing...
June 2018: Journal of the Acoustical Society of America
E Hafla, E Johnson, C N Johnson, L Preston, D Aldridge, J D Roberts
Marine hydrokinetic (MHK) devices generate electricity from the motion of tidal and ocean currents, as well as ocean waves, to provide an additional source of renewable energy available to the United States. These devices are a source of anthropogenic noise in the marine ecosystem and must meet regulatory guidelines that mandate a maximum amount of noise that may be generated. In the absence of measured levels from in situ deployments, a model for predicting the propagation of sound from an array of MHK sources in a real environment is essential...
June 2018: Journal of the Acoustical Society of America
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