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Journal of the Acoustical Society of America

Noam R Shabtai, Gottfried Behler, Michael Vorländer, Stefan Weinzierl
A database of acoustic radiation patterns was recorded, modeled, and analyzed for 41 modern or authentic orchestral musical instruments. The generation of this database included recordings of each instrument over the entire chromatic tone range in an anechoic chamber using a surrounding spherical microphone array. Acoustic source centering was applied in order to align the acoustic center of the sound source to the physical center of the microphone array. The acoustic radiation pattern is generated in the spherical harmonics domain at each harmonic partial of each played tone...
February 2017: Journal of the Acoustical Society of America
A Westermann, J M Buchholz
Westermann and Buchholz [(2015). J. Acoust. Soc. Am. 137(2), 757-767] found substantial improvements in speech reception thresholds (SRTs) for normal hearing listeners in a reverberant auditorium when the target talker was separated in distance from a two-talker masker. This study applied similar methodology, but tested listeners with a hearing impairment. On average, the participants received a 7 dB benefit in SRTs when the target was fixed at 0.5 m and the masker was moved from 0.5 to 10 m. But when the target was moved away, the SRTs increased by 5 dB...
February 2017: Journal of the Acoustical Society of America
Daniel Fogerty, William J Bologna, Jayne B Ahlstrom, Judy R Dubno
Fluctuating noise, common in everyday environments, has the potential to mask acoustic cues important for speech recognition. This study examined the extent to which acoustic cues for perception of vowels and stop consonants differ in their susceptibility to simultaneous and forward masking. Younger normal-hearing, older normal-hearing, and older hearing-impaired adults identified initial and final consonants or vowels in noise-masked syllables that had been spectrally shaped. The amount of shaping was determined by subjects' audiometric thresholds...
February 2017: Journal of the Acoustical Society of America
Kevin D Heaney, Mark Prior, Richard L Campbell
The ocean is nearly transparent to low frequency sound permitting the observation of distant events such as earthquakes or explosions at fully basin scales. For very low frequency the ocean acts as a shallow-water waveguide and lateral variability in bathymetry can lead to out-of-plane effects. In this paper, data from the International Monitoring System of the Comprehensive Test Ban Treaty Organization (CTBTO) is used to present two cases where robustly localized seismic events in locations clearly within the two-dimensional (2-D) shadow of a continent or large island generate T-phase signals that are received on a hydro-acoustic station...
February 2017: Journal of the Acoustical Society of America
Roger Waxler, Jelle Assink, Doru Velea
The use of expansions in vertical eigenmodes for long range infrasound propagation modeling in the effective sound speed approximation is investigated. The question of convergence of such expansions is related to the maximum elevation angles that are required. Including atmospheric attenuation leads to a non-self-adjoint vertical eigenvalue problem. The use of leading order perturbation theory for the modal attenuation is compared to the results of numerical solutions to the non-self-adjoint eigenvalue problem and conditions under which the perturbative result is expected to be valid are obtained...
February 2017: Journal of the Acoustical Society of America
Ting Wang, Meiping Sheng, Qinghua Qin
In the context of sound incident upon a metamaterial plate, explicit formulas for sound transmission loss (STL) are derived in the presence of external mean flow. Metamaterial plate, consisting of homogeneous plate and lateral local resonators (LLRs), is homogenized by using effective medium method to obtain the effective mass density and facilitate the calculation of STL. Results show that (a) vigorously oscillating LLRs lead to higher STL compared with bare plate, (b) increasing Mach number of the external mean flow helps obtain higher STL below the coincidence frequency but decreases STL above the coincidence frequency due to the added mass effect of light fluid loading and aerodynamic damping effect, (c) the coincidence frequency shifts to higher frequency range for the refracted effect of the external mean flow...
February 2017: Journal of the Acoustical Society of America
Yuzhou Liu, DeLiang Wang
Multipitch tracking is important for speech and signal processing. However, it is challenging to design an algorithm that achieves accurate pitch estimation and correct speaker assignment at the same time. In this paper, deep neural networks (DNNs) are used to model the probabilistic pitch states of two simultaneous speakers. To capture speaker-dependent information, two types of DNN with different training strategies are proposed. The first is trained for each speaker enrolled in the system (speaker-dependent DNN), and the second is trained for each speaker pair (speaker-pair-dependent DNN)...
February 2017: Journal of the Acoustical Society of America
Jamie Macaulay, Jonathan Gordon, Douglas Gillespie, Chloë Malinka, Simon Northridge
The growing interest in generating electrical power from tidal currents using tidal turbine generators raises a number of environmental concerns, including the risk that marine mammals might be injured or killed through collision with rotating turbine blades. To understand this risk, information on how marine mammals use tidal rapid habitats and in particular, their underwater movements and dive behaviour is required. Porpoises, which are the most abundant small cetacean at most European tidal sites, are difficult animals to tag, and the limited size of tidal habitats means that any telemetered animal would be likely to spend only a small proportion of time within them...
February 2017: Journal of the Acoustical Society of America
Jean-Michel Attendu, Annie Ross
Nearfield acoustical holography can be used to visualize time domain evolution of non-stationary sound fields. It requires sampling of the pressure field with a microphone array to calculate the sound field on other parallel surfaces, either toward the source or farther away from it. This paper focuses on forward propagation of fields sampled with a planar array. Several formulations exist to perform such calculation; however, despite being mathematically well-posed, they generate significant errors, especially for larger propagation distances...
February 2017: Journal of the Acoustical Society of America
Carlos Barajas, Eric Johnsen
In certain cavitation-based ultrasound techniques, the relative importance of thermally vs mechanically induced damage is unclear. As a first step to investigate this matter, a numerical model for bubble dynamics in tissue-like, viscoelastic media is presented in which full thermal effects are included inside and outside the bubble, as well as interdiffusion of vapor and non-condensible gas inside the bubble. Soft tissue is assumed to behave according to a Kelvin-Voigt model in which viscous and elastic contributions are additive...
February 2017: Journal of the Acoustical Society of America
Xu Wang, Wuzhou Yu, Xingyi Zhu, Zaixiu Jiang, Dongxing Mao
The screening effect of a roadside balcony deteriorates considerably due to sound reflection from its ceiling. Nonetheless, this drawback can be eliminated by artificially steering the reflected sound away from the building facade, which is achieved by introducing impedance inhomogeneity to the ceiling surface. This paper presents an elaborated investigation on the effect of the phase gradient of a ceiling surface on screening exterior noise, theoretically and numerically. By balancing its sound-steering capability and performance fluctuation level, such a balcony ceiling may have the potential to be widely used on roadside buildings...
February 2017: Journal of the Acoustical Society of America
Nail A Gumerov, Iskander S Akhatov
The paper is dedicated to mathematical modeling of self-organization of bubbly liquids in acoustic fields. A continuum model describing the two-way interaction of diluted polydisperse bubbly liquids and acoustic fields in weakly-nonlinear approximation is studied analytically and numerically in the one-dimensional case. It is shown that the regimes of self-organization of monodisperse bubbly liquids can be controlled by only a few dimensionless parameters. Two basic modes, clustering and propagating shock waves of void fraction (acoustically induced transparency), are identified and criteria for their realization in the space of parameters are proposed...
February 2017: Journal of the Acoustical Society of America
J Antunes, V Debut
Most musical instruments consist of dynamical subsystems connected at a number of constraining points through which energy flows. For physical sound synthesis, one important difficulty deals with enforcing these coupling constraints. While standard techniques include the use of Lagrange multipliers or penalty methods, in this paper, a different approach is explored, the Udwadia-Kalaba (U-K) formulation, which is rooted on analytical dynamics but avoids the use of Lagrange multipliers. This general and elegant formulation has been nearly exclusively used for conceptual systems of discrete masses or articulated rigid bodies, namely, in robotics...
February 2017: Journal of the Acoustical Society of America
Ning Xiang
No abstract text is available yet for this article.
February 2017: Journal of the Acoustical Society of America
Tobias Neher
To scrutinize the binaural contribution to speech-in-noise reception, four groups of elderly participants with or without audiometric asymmetry <2 kHz and with or without near-normal binaural intelligibility level difference (BILD) completed tests of monaural and binaural phase sensitivity as well as cognitive function. Groups did not differ in age, overall degree of hearing loss, or cognitive function. Analyses revealed an influence of BILD status but not audiometric asymmetry on monaural phase sensitivity, strong correlations between monaural and binaural detection thresholds, and monaural and binaural but not cognitive BILD contributions...
February 2017: Journal of the Acoustical Society of America
Sergey I Voropayev, Nicholas C Ovenden, Harindra J S Fernando, Paul R Donovan
Scaled acoustic laboratory experiments are used to develop a methodology for obtaining the acoustic characteristics of different barrier top designs and for identifying geometries that may have advantages over the traditional thin vertical screen. The idea is to use a short impulsive spherical sound pulse possessing a broad frequency spectrum. If the duration of the pulse is sufficiently short, the entire primary signal, which travels by the shortest direct route diffracting at the top of the barrier, arrives at the receiver much earlier than any secondary signals reflected from the surroundings...
February 2017: Journal of the Acoustical Society of America
Fernando Llanos, Joshua M Alexander, Christian E Stilp, Keith R Kluender
While all languages differentiate speech sounds by manner of articulation, none of the acoustic correlates proposed to date seem to account for how these contrasts are encoded in the speech signal. The present study describes power spectral entropy (PSE), which quantifies the amount of potential information conveyed in the power spectrum of a given sound. Results of acoustic analyses of speech samples extracted from the Texas Instruments-Massachusetts Institute of Technology database reveal a statistically significant correspondence between PSE and American English major classes of manner of articulation...
February 2017: Journal of the Acoustical Society of America
Jillian M Sills, Brandon L Southall, Colleen Reichmuth
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...
February 2017: Journal of the Acoustical Society of America
Weihai Huang, Deping Yu, Min Zhang, Fengfei Ye, Jin Yao
Ultrasonic elliptical vibration cutting (UEVC) is effective in ultraprecision diamond cutting of hard-brittle materials and ferrous metals. However, its design is quite empirical and tedious. This paper proposes an analytical design method for developing the UEVC device which works at the Flexural-Flexural complex-mode to generate the elliptical vibration. For such UEVC device, the resonant frequencies of the two flexural vibrations are required to be the same. In addition, the nodal points of the two flexural vibrations should be coincident so that the device can be clamped without affecting the vibrations...
February 2017: Journal of the Acoustical Society of America
Amy M Van Cise, Marie A Roch, Robin W Baird, T Aran Mooney, Jay Barlow
Divergence in acoustic signals used by different populations of marine mammals can be caused by a variety of environmental, hereditary, or social factors, and can indicate isolation between those populations. Two types of genetically and morphologically distinct short-finned pilot whales, called the Naisa- and Shiho-types when first described off Japan, have been identified in the Pacific Ocean. Acoustic differentiation between these types would support their designation as sub-species or species, and improve the understanding of their distribution in areas where genetic samples are difficult to obtain...
February 2017: Journal of the Acoustical Society of America
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