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Oct 2011

Volume 130, Issue 4, pp. EL129-2575

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A note about insensitivity to pitch-change direction

Samuel R. Mathias, Peter J. Bailey, Catherine Semal, and Laurent Demany

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL129-EL134 (2011); (6 pages)

Online Publication Date: 08 Sep 2011

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Some listeners are insensitive to the direction of pure-tone frequency changes when the standard frequency is roved widely over trials, but less so when the standard frequency is fixed and trial-by-trial feedback is provided. The present experiment tested the hypothesis that fixing the standard frequency and providing feedback is advantageous for direction-impaired listeners because under these conditions the listeners can learn to respond correctly without genuinely perceiving frequency-change direction. This hypothesis was ruled out by the experiment. It appears instead that direction-impaired listeners find it difficult to ignore the irrelevant frequency changes introduced by roving.
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43.66.Hg Pitch
43.66.Fe Discrimination: intensity and frequency
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Scattering of a spherical wave by a small sphere: An elementary solution

Oleg A. Godin

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL135-EL141 (2011); (7 pages) | Cited 2 times

Online Publication Date: 08 Sep 2011

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Wave scattering by objects that are small compared to the wavelength (Rayleigh scattering) is usually studied for plane incident waves. However, knowledge of the full Green’s function of the problem becomes necessary when the separation of scatterers from either an interface or each other is comparable to the scatterers’ dimensions. Here, an elementary analytic solution is derived for diffraction of a spherical sound wave by a small, soft sphere. The approximate solution is obtained from asymptotic expansions of an exact solution, holds everywhere outside the sphere, and reduces to classical results due to Kelvin and Rayleigh in appropriate special cases.
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43.20.El Reflection, refraction, diffraction of acoustic waves
43.20.Fn Scattering of acoustic waves
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Modification of digital music files for use in human temporary threshold shift studies

C. G. Le Prell, Q. Yang, and J. G. Harris

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL142-EL146 (2011); (5 pages)

Online Publication Date: 08 Sep 2011

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An exposure that is reproducible across clinical/laboratory environments, and appealing to subjects, is described here. Digital music files are level-equated within and across songs such that playlists deliver an exposure that is consistent across time. Modified music is more pleasant to listen to than pure tones or shaped noise, and closely follows music exposures subjects may normally experience. Multiple therapeutics reduce noise-induced hearing loss in animals but human trial design is complicated by limited access to noise-exposed subject populations. The development of standard music exposure parameters for temporary threshold shift studies would allow comparison of protection across agents with real-world relevant stimuli in human subjects.
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43.75.Zz Analysis, synthesis, and processing of musical sounds
43.75.Wx Electronic and computer music
43.75.Yy Instrumentation and measurement methods for musical acoustics
43.58.Fm Sound level meters, level recorders, sound pressure, particle velocity, and sound intensity measurements, meters, and controllers
43.58.Vb Calibration of acoustical devices and systems
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Developmental changes in ultrasonic vocalizations by infant Japanese echolocating bats, Pipistrellus abramus

Shizuko Hiryu and Hiroshi Riquimaroux

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL147-EL153 (2011); (7 pages) | Cited 1 time

Online Publication Date: 08 Sep 2011

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Developmental changes in vocalizations by Pipistrellus abramus were investigated during the first post-natal month. Vocalizations by pups on the day of birth were frequency-modulated ultrasounds from 30.0 ± 4.0 kHz to 19.3 ± 1.9 kHz with multiple harmonics. The terminal frequency of the second harmonic (TF2) of pup vocalizations corresponded to that of the fundamental (TF1) in adult bats (41.4 ± 2.6 kHz), suggesting that pup vocalizations can be easily detected by the mother. In addition, there are two types of infant vocalization: short duration echolocation precursor and long duration isolation calls, which showed separate developmental patterns over time.
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43.80.Ka Sound production by animals: mechanisms, characteristics, populations, biosonar
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Range aliasing in frequency coherent geoacoustic inversion

Caglar Yardim, Peter Gerstoft, and William S. Hodgkiss

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL154-EL160 (2011); (7 pages) | Cited 1 time

Online Publication Date: 08 Sep 2011

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This paper discusses the effects of frequency selection on source localization and geoacoustic inversion methods that use frequency coherent objective functions. Matched-field processors based on frequency-coherent objective functions often have rapidly fluctuating range ambiguity surfaces. Insufficient sampling in frequency domain results in range aliasing terms that affect geoacoustic inversion. Range aliasing and its effects on source localization and environmental parameter inversion are demonstrated on data collected during the MAPEX2000 experiment. Guidance for frequency selection to avoid range aliasing is provided.
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43.60.Ac Theory of acoustic signal processing
43.60.Jn Source localization and parameter estimation
43.30.Pc Ocean parameter estimation by acoustical methods; remote sensing; imaging, inversion, acoustic tomography
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Time reversal communication in a time-varying sparse channel

H. C. Song

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL161-EL166 (2011); (6 pages) | Cited 4 times

Online Publication Date: 08 Sep 2011

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Recently time reversal (TR) communications has been extended to time-varying channels. The basic idea is to implement it on a block-by-block basis such that within each block the channel remains time-invariant and subsequently is updated using detected symbols (decision-directed mode). Using experimental data (12–20 kHz) collected in shallow water, this letter investigates three different block-based TR approaches: (1) without explicit phase tracking, (2) with phase tracking, and (3) exploiting channel sparsity. The TR approaches then are compared to a conventional adaptive multichannel equalizer. It is found that approach (3) generally provides the best performance and robustness.
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43.60.Dh Signal processing for communications: telephony and telemetry, sound pickup and reproduction, multimedia
43.60.Gk Space-time signal processing, other than matched field processing
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Use of parabolic reflector to amplify in-air signals generated during impact-echo testing

Xiaowei Dai, Jinying Zhu, Yi-Te Tsai, and Michael R. Haberman

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL167-EL172 (2011); (6 pages) | Cited 1 time

Online Publication Date: 08 Sep 2011

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The impact-echo method is a commonly used nondestructive testing technique for elastic plates in civil engineering. The impact-echo mode corresponds to the frequency at zero group velocity of S1 Lamb mode. Recent development of the air-coupled impact-echo (ACIE) method introduces the possibility for rapid scanning of large structures and increases the practicality of in situ measurements. However, sensors used in ACIE are susceptible to ambient noise, which complicates in situ ACIE measurements. This letter presents the results of ACIE measurements taken using a parabolic reflector together with standard measurement microphones to increase the signal to noise ratio for ACIE measurements. The signal gain and effects of sensor location with respect to impact location are discussed.
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43.40.Dx Vibrations of membranes and plates
43.20.Mv Waveguides, wave propagation in tubes and ducts
43.35.Yb Ultrasonic instrumentation and measurement techniques
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Noise interferometry in an inhomogeneous environment in the geometric limit

Michael G. Brown

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL173-EL179 (2011); (7 pages)

Online Publication Date: 08 Sep 2011

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An approximation to the transient Green’s function G(xa|xb,t) between points xa and xb can be estimated by taking the time derivative of the correlation function Cab(t) of records of ambient noise measured at locations xa and xb. From the general relationship between Cab(t) and G(xa|xb,t) it is shown, using a stationary-phase-like argument, that in an inhomogeneous environment in the geometric limit Cab(t) consists of a superposition of signed step functions and two-sided logarithmic singularities that are delayed in time by the travel times of the rays connecting xa and xb.
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43.30.Cq Ray propagation of sound in water
43.30.Nb Noise in water; generation mechanisms and characteristics of the field
43.60.Gk Space-time signal processing, other than matched field processing
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Accounting for the stability of microbubbles to multi-pulse excitation using a lipid-shedding model

Jean-Pierre O’Brien, Nick Ovenden, and Eleanor Stride

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL180-EL185 (2011); (6 pages) | Cited 2 times

Online Publication Date: 08 Sep 2011

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Interest in microbubble ultrasound contrast agents as therapeutic and quantitative imaging tools has increased the need for accurate modeling of their behavior. Experiments have shown that some bubbles shrink significantly over the course of a single pulse but that the bubbles may eventually reach a stable size after many insonations. Here, it is shown from dimensional arguments that diffusion phenomena are negligible on the time scales that characterize a typical ultrasound pulse. Subsequently, a new model describing both a lipid-shedding mechanism and a nonlinear surface viscosity is developed and shown to provide a more accurate description of the observed experimental behavior.
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43.25.Yw Nonlinear acoustics of bubbly liquids
43.35.Ei Acoustic cavitation in liquids
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Native dialect matters: Perceptual assimilation of Dutch vowels by Czech listeners

Kateřina Chládková and Václav Jonáš Podlipský

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL186-EL192 (2011); (7 pages) | Cited 1 time

Online Publication Date: 08 Sep 2011

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Naive listeners’ perceptual assimilations of non-native vowels to first-language (L1) categories can predict difficulties in the acquisition of second-language vowel systems. This study demonstrates that listeners having two slightly different dialects as their L1s can differ in the perception of foreign vowels. Specifically, the study shows that Bohemian Czech and Moravian Czech listeners assimilate Dutch high front vowels differently to L1 categories. Consequently, the listeners are predicted to follow different paths in acquiring these Dutch vowels. These findings underscore the importance of carefully considering the specific dialect background of participants in foreign- and second-language speech perception studies.
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43.71.Hw Cross-language perception of speech
43.71.Es Vowel and consonant perception; perception of words, sentences, and fluent speech
43.71.An Models and theories of speech perception
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Influence of pitch, loudness, and timbre on the perception of instrument dynamics

Marco Fabiani and Anders Friberg

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL193-EL199 (2011); (7 pages) | Cited 1 time

Online Publication Date: 08 Sep 2011

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The effect of variations in pitch, loudness, and timbre on the perception of the dynamics of isolated instrumental tones is investigated. A full factorial design was used in a listening experiment. The subjects were asked to indicate the perceived dynamics of each stimulus on a scale from pianissimo to fortissimo. Statistical analysis showed that for the instruments included (i.e., clarinet, flute, piano, trumpet, and violin) timbre and loudness had equally large effects, while pitch was relevant mostly for the first three. The results confirmed our hypothesis that loudness alone is not a reliable estimate of the dynamics of musical tones.
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43.75.Cd Music perception and cognition
43.66.Lj Perceptual effects of sound
43.66.Jh Timbre, timbre in musical acoustics
43.66.Hg Pitch
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Stochastic channel simulator based on local scattering functions

Y. Isukapalli, H. C. Song, and W. S. Hodgkiss

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL200-EL205 (2011); (6 pages)

Online Publication Date: 08 Sep 2011

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This letter addresses the limitations of the stochastic channel simulation approach employed in wireless channels when directly applied to underwater channels. First it is shown analytically why the simulation method fails when the correlated taps each have a different Doppler spectrum. Then, based on the idea of local scattering functions, we propose a simple solution to the problem of simulating a channel with correlated taps where the correlated taps occur in subgroups with each of the subgroups having a different Doppler spectrum, applicable to underwater channels. Our simulation approach is tested successfully on the KAM08 channel.
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43.60.Dh Signal processing for communications: telephony and telemetry, sound pickup and reproduction, multimedia
43.60.Cg Statistical properties of signals and noise
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Enhanced bimodal distributions facilitate the learning of second language vowels

Paola Escudero, Titia Benders, and Karin Wanrooij

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL206-EL212 (2011); (7 pages) | Cited 3 times

Online Publication Date: 09 Sep 2011

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This study addresses the questions of whether listening to a bimodal distribution of vowels improves adult learners’ categorization of a difficult L2 vowel contrast and whether enhancing the acoustic differences between the vowels in the distribution yields better categorization performance. Spanish learners of Dutch were trained on a natural bimodal or an enhanced bimodal distribution of the Dutch vowels /ɑ/ and /aː/, with the average productions of the vowels or more extreme values as the endpoints respectively. Categorization improved for learners who listened to the enhanced distribution, which suggests that adults profit from input with properties similar to infant-directed speech.
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43.71.Ft Development of speech perception
43.71.Es Vowel and consonant perception; perception of words, sentences, and fluent speech
43.71.An Models and theories of speech perception
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Nonlinear optoacoustic transformation in the system of dielectric substrate/submicron metal coating/liquid

Daria S. Kopylova and Ivan M. Pelivanov

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL213-EL218 (2011); (6 pages) | Cited 1 time

Online Publication Date: 09 Sep 2011

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The optoacoustic method has been shown to be an accurate technique for the measurement of the properties of submicron metal coatings deposited on a dielectric substrate, i.e., mirrors. The method has been previously theoretically described in terms of a linear model of optoacoustic transformation in a system substrate/coating/liquid. The goal of the present work was to determine the limits at which the linear model is still applicable. The modification of the laser induced acoustic signal profiles and transfer functions of optoacoustic transformation versus the laser fluence was studied for two liquids: ethanol and water.
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43.35.Sx Acoustooptical effects, optoacoustics, acoustical visualization, acoustical microscopy, and acoustical holography
43.35.Ns Acoustical properties of thin films
43.35.Ud Thermoacoustics, high temperature acoustics, photoacoustic effect
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Time reversal reconstruction of finite sized sources in elastic media

Brian E. Anderson, Michele Griffa, Timothy J. Ulrich, and Paul A. Johnson

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL219-EL225 (2011); (7 pages) | Cited 1 time

Online Publication Date: 09 Sep 2011

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The ability of the time reversal process to reconstruct sources of finite size relative to a wavelength is investigated. Specifically the quality of the spatial reconstruction of a finite sized source will be presented through the use of time reversal experiments conducted on an aluminum plate. The data presented in the paper show that time reversal can reconstruct a source equally well regarding less of its size, when the source is a half wavelength or less in size. The quality of spatial reconstruction when the source is larger than a half wavelength progressively decreases with the size of the source.
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43.60.Tj Wave front reconstruction, acoustic time-reversal, and phase conjugation
43.60.Lq Acoustic imaging, displays, pattern recognition, feature extraction
43.40.Le Techniques for nondestructive evaluation and monitoring, acoustic emission
43.40.Ph Seismology and geophysical prospecting; seismographs
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Cross-language perceptual similarity predicts categorial discrimination of American vowels by naïve Japanese listeners

Winifred Strange, Miwako Hisagi, Reiko Akahane-Yamada, and Rieko Kubo

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL226-EL231 (2011); (6 pages)

Online Publication Date: 09 Sep 2011

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Current speech perception models propose that relative perceptual difficulties with non-native segmental contrasts can be predicted from cross-language phonetic similarities. Japanese (J) listeners performed a categorical discrimination task in which nine contrasts (six adjacent height pairs, three front/back pairs) involving eight American (AE) vowels [iː, ɪ, ɛ, æː, ɑː, ʌ, ʊ, uː] in /hVbə/ disyllables were tested. The listeners also completed a perceptual assimilation task (categorization as J vowels with category goodness ratings). Perceptual assimilation patterns (quantified as categorization overlap scores) were highly predictive of discrimination accuracy (rs = 0.93). Results suggested that J listeners used both spectral and temporal information in discriminating vowel contrasts.
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43.71.Hw Cross-language perception of speech
43.71.Es Vowel and consonant perception; perception of words, sentences, and fluent speech
43.71.An Models and theories of speech perception
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Beamforming using compressive sensing

Geoffrey F. Edelmann and Charles F. Gaumond

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL232-EL237 (2011); (6 pages) | Cited 1 time

Online Publication Date: 09 Sep 2011

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Compressive sensing (CS) is compared with conventional beamforming using horizontal beamforming of at-sea, towed-array data. They are compared qualitatively using bearing time records and quantitatively using signal-to-interference ratio. Qualitatively, CS exhibits lower levels of background interference than conventional beamforming. Furthermore, bearing time records show increasing, but tolerable, levels of background interference when the number of elements is decreased. For the full array, CS generates signal-to-interference ratio of 12 dB, but conventional beamforming only 8 dB. The superiority of CS over conventional beamforming is much more pronounced with undersampling.
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43.30.Wi Passive sonar systems and algorithms, matched field processing in underwater acoustics
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Calibration of otoacoustic emission probe microphones

Daniel M. Rasetshwane and Stephen T. Neely

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL238-EL243 (2011); (6 pages)

Online Publication Date: 13 Sep 2011

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Recently, investigators of otoacoustic emissions (OAEs) have shown interest in measuring OAEs to frequencies higher than 10 kHz. Most commercial instruments used to measure OAEs do not specify the microphone frequency response at higher frequencies, nor does their typically integrated design make it convenient to measure it. OAE probes manufactured by Etymotic Research have reasonably constant microphone sensitivity up to about 10 kHz and allow direct access to both the sound sources and microphone preamplifier output. A detailed procedure for calibrating the Etymotic Research OAE probe microphone to extend its usable frequency range to frequencies up to 20 kHz is described.
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43.64.Jb Otoacoustic emissions
43.58.Vb Calibration of acoustical devices and systems
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The effects of non-cardioid directivity on incidence angle estimation using the polar energy time curve

J. James Esplin, Brian E. Anderson, Timothy W. Leishman, and Brian T. Thornock

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL244-EL250 (2011); (7 pages)

Online Publication Date: 13 Sep 2011

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Assessment of desirable reflections and control of undesirable reflections in rooms are best accomplished if the reflecting surfaces are properly localized. Several measurement techniques exist to identify the incident direction of reflected sound, including the useful polar energy time curve (Polar ETC), which requires six cardioid impulse response measurements along the Cartesian axes. The purpose of this investigation is to quantify the incidence angle estimation error introduced into the Polar ETC by non-cardioid microphone directivities. The results demonstrate that errors may be minimized with a cardioid-family microphone possessing a certain range of directivities and by maximizing the measurement signal-to-noise ratio.
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43.55.Mc Room acoustics measuring instruments, computer measurement of room properties
43.58.Fm Sound level meters, level recorders, sound pressure, particle velocity, and sound intensity measurements, meters, and controllers
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Automatic speech recognition using articulatory features from subject-independent acoustic-to-articulatory inversion

Prasanta Kumar Ghosh and Shrikanth Narayanan

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL251-EL257 (2011); (7 pages) | Cited 1 time

Online Publication Date: 14 Sep 2011

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An automatic speech recognition approach is presented which uses articulatory features estimated by a subject-independent acoustic-to-articulatory inversion. The inversion allows estimation of articulatory features from any talker’s speech acoustics using only an exemplary subject’s articulatory-to-acoustic map. Results are reported on a broad class phonetic classification experiment on speech from English talkers using data from three distinct English talkers as exemplars for inversion. Results indicate that the inclusion of the articulatory information improves classification accuracy but the improvement is more significant when the speaking style of the exemplar and the talker are matched compared to when they are mismatched.
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43.72.Ar Speech analysis and analysis techniques; parametric representation of speech
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Probing the interior of a solid volume with time reversal and nonlinear elastic wave spectroscopy

P. Y. Le Bas, T. J. Ulrich, B. E. Anderson, R. A. Guyer, and P. A. Johnson

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL258-EL263 (2011); (6 pages)

Online Publication Date: 15 Sep 2011

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A nonlinear scatterer is simulated in the body of a sample and demonstrates a technique to locate and define the elastic nature of the scatterer. Using the principle of time reversal, elastic wave energy is focused at the interface between blocks of optical grade glass and aluminum. Focusing of energy at the interface creates nonlinear wave scattering that can be detected on the sample perimeter with time-reversal mirror elements. The nonlinearly generated scattered signal is bandpass filtered about the nonlinearly generated components, time reversed and broadcast from the same mirror elements, and the signal is focused at the scattering location on the interface.
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43.25.Dc Nonlinear acoustics of solids
43.25.Zx Measurement methods and instrumentation for nonlinear acoustics
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Effects of roving level and spectral range on vowel formant discrimination

Chang Liu

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL264-EL270 (2011); (7 pages)

Online Publication Date: 15 Sep 2011

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Thresholds of vowel formant discrimination for F1 and F2 of isolated vowels with full and partial vowel spectra were measured for normal-hearing listeners at fixed and roving speech levels. Performance of formant discrimination was significantly better for fixed levels than for roving levels with both full and partial spectra. The effect of vowel spectral range was present only for roving levels, but not for fixed levels. These results, consistent with studies of profile analysis, indicated different perceptual mechanisms for listeners to discriminate vowel formant frequency at fixed and roving levels.
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43.71.Es Vowel and consonant perception; perception of words, sentences, and fluent speech
43.66.Fe Discrimination: intensity and frequency
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Separation of zeros for source signature identification under reverberant path conditions

Tomomi Hasegawa and Mikio Tohyama

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. EL271-EL275 (2011); (5 pages)

Online Publication Date: 15 Sep 2011

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This paper presents an approach to distinguishing the zeros representing a sound source from those representing the transfer function on the basis of Lyon’s residue-sign model. In machinery noise diagnostics, the source signature must be separated from observation records under reverberant path conditions. In numerical examples and an experimental piano-string vibration analysis, the modal responses could be synthesized by using clustered line-spectrum modeling. The modeling error represented the source signature subject to the source characteristics being given by a finite impulse response. The modeling error can be interpreted as a remainder function necessary for the zeros representing the source signature.
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43.40.At Experimental and theoretical studies of vibrating systems
43.40.Sk Inverse problems in structural acoustics and vibration
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Harvesting mechanical energy via structural vibrations

John J. McCoy

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. 1783-1786 (2011); (4 pages) | Cited 1 time

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Abstract Unavailable
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43.10.Gi Editorials, Forum
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Ambient noise in large rivers (L)

Miodrag S. Vračar and Miomir Mijić

J. Acoust. Soc. Am. Volume 130, Issue 4, pp. 1787-1791 (2011); (5 pages)

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This paper presents the results of hydroacoustic noise research in three large European rivers: the Danube, the Sava, and the Tisa. Noise in these rivers was observed during a period of ten years, which includes all annual variation in hydrological and meteorological conditions (flow rate, speed of flow, wind speed, etc.). Noise spectra are characterized by wide maximums at frequencies between 20 and 30 Hz, and relatively constant slope toward higher frequencies. Spectral level of noise changes in time in relatively wide limits. At low frequencies, below 100 Hz, the dynamics of noise level is correlated with the dynamics of water flow and speed. At higher frequencies, noise spectra are mostly influenced by human activities on river and on riverbanks. The influence of wind on noise in rivers is complex due to the annual variation of river surface. The influence of wind is less pronounced than in oceans, seas, and lakes.
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43.30.Nb Noise in water; generation mechanisms and characteristics of the field
43.50.Cb Noise spectra, determination of sound power
43.50.Ed Noise generation
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