Volume 134, Issue 1, July 2013
- jasa express letters
- letters to the editor
- aeroacoustics, atmospheric sound 
- underwater sound 
- sediment acoustics 
- ultrasonics, quantum acoustics, and physical effects of sound 
- transduction 
- structural acoustics and vibration 
- noise: its effects and control 
- architectural acoustics 
- acoustic signal processing 
- physiological acoustics 
- psychological acoustics 
- speech production 
- speech perception 
- speech processing and communication systems 
- music and musical instruments 
- bioacoustics 
- acoustical news
- acoustical standards news
- reviews of acoustical patents
- part 2 special issue on sca soundscapes and applications
Index of content:
- JASA EXPRESS LETTERS
134(2013); http://dx.doi.org/10.1121/1.4807430View Description Hide Description
Observations of underwater noise from impact pile driving were made with a vertical line array. Previous studies [Reinhall and Dahl, J. Acoust. Soc. Am. 130, 1209–1216 (2011)] show that the dominant underwater noise from impact driving is from the Mach wave associated with the radial expansion of the pile that propagates down the pile at supersonic speed after impact. Here precise estimates of the vertical arrival angles associated with the down- and up-going Mach wave are made via beam forming, and the energy budget of the arrival structure is quantified.
134(2013); http://dx.doi.org/10.1121/1.4804945View Description Hide Description
Detailed knowledge of sound speed profiles and the sound speed profile's spatial and temporal variability resulting from internal waves (IWs) are indispensable to investigating significant acoustic field fluctuations in shallow water. A strategy to obtain a time-varying, three-dimensional (3D) IW temperature field is presented. It uses two types of simultaneous measurements: dense observations from a farm of thermistor strings and IW surface expressions from a ship-based radar. Using data from the Shallow Water 2006 experiment, the temperature field, over multiple kilometers in range, was reconstructed and, fed to a 3D acoustic model to demonstrate IW impacts on acoustic propagation.
Frequency-change aftereffect produced by adaptation to real and illusory unidirectional frequency sweeps134(2013); http://dx.doi.org/10.1121/1.4807304View Description Hide Description
It was examined whether illusory and real continuities induce the frequency-change aftereffect, in which repeated exposure to a frequency sweep results in a shift in the perceived frequency change direction of a subsequent test sound. The magnitude of the aftereffect for different types of adaptors (“real sweep,” “illusory sweep,” and “sweep with gap”) was compared. Listeners judged the direction of a frequency change of the test sound and showed a significant aftereffect only for the “real sweep” adaptors. The results suggest that the illusory sweeps are processed after the stage of frequency-change detection.
134(2013); http://dx.doi.org/10.1121/1.4807431View Description Hide Description
Categorical perception experiments were performed on an English /b-p/ voice onset time (VOT) continuum with native (American English) and non-native (Korean) listeners to examine whether and how phonetic categorization is modulated by prosodic boundary and language experience. Results demonstrated perceptual shifting according to prosodic boundary strength: A longer VOT was required to identify a sound as /p/ after an intonational phrase than a word boundary, regardless of the listeners' language experience. This suggests that segmental perception is modulated by the listeners' computation of an abstract prosodic structure reflected in phonetic cues of phrase-final lengthening and domain-initial strengthening, which are common across languages.
134(2013); http://dx.doi.org/10.1121/1.4807432View Description Hide Description
Effects of word-level phonetic variation on the recognition of words with different pronunciation variants (e.g., center produced with/(out) [t]) are investigated via the semantic- and pseudoword-priming paradigms. A bias favoring clearly articulated words with canonical variants ([nt]) is found. By reducing the bias, words with different variants show robust and equivalent lexical activation. The equivalence of different word forms highlights a snag for frequency-based theories of lexical access: How are words and word productions with vastly different frequencies recognized equally well by listeners? A process-based account is proposed, suggesting that careful speech induces bottom-up processing and casual speech induces top-down processing.
134(2013); http://dx.doi.org/10.1121/1.4804944View Description Hide Description
A previous report [Margolis and Stiepan (2012). “Acoustic method for calibration of audiometric bone vibrators,” J. Acoust. Soc. Am. 131, 1221–1225] described a reliable, inexpensive, acoustic method for calibration of audiometric bone vibrators. As a follow up to that report harmonic distortion measurements were made with the standard electromechanical method and the acoustic method using five Radioear B71 vibrators and one Radioear B81 prototype vibrator. Lower distortion was seen for measurements made with the acoustic method compared to the electromechanical method and for the Radioear B81 vibrator compared to the Radioear B71 vibrator.
134(2013); http://dx.doi.org/10.1121/1.4808111View Description Hide Description
In the Born approximation, the acoustic scattering from a spherical obstacle of a size comparable to the acoustic wavelength can be evaluated in the framework of the sensitivity kernel approach, which describes the relationship between the pressure-field fluctuation and the position of a local change in the propagation medium. The spatial structure of the sensitivity kernel is here investigated through experimental observations made in a water tank at the ultrasonic scale and compared to an analytical model. The pattern of the sensitivity kernel is discussed in the case of a source-to-receiver wave field that includes a direct path and one surface reflection.
134(2013); http://dx.doi.org/10.1121/1.4809775View Description Hide Description
Vowels are lengthened in lexically stressed syllables and also in word-final syllables. Both stress and final-syllable lengthening can assist in word segmentation from continuous speech, but in languages like English, with a preponderance of stress-initial words, lengthening cues may conflict for indicating word boundaries. An analysis of a large corpus of English speech demonstrated that speakers provide distributional information sufficient to potentially allow listeners to determine whether vowel lengthening is associated with lexical stress or word finality without relying on a congruence of multiple suprasegmental cues to make the distinction.
134(2013); http://dx.doi.org/10.1121/1.4809773View Description Hide Description
This paper describes the principle behind a high amplitude non-contact acoustic source based on the principle of time reversal (TR), a process to focus energy at a point in space. By doing the TR in an air filled, hollow cavity and using a laser vibrometer in the calibration of the system, a non-contact source may be created. This source is proven to be more energetic than an off the shelf focused ultrasound transducer. A scaled up version of the proposed source has the potential to allow nondestructive evaluation processes that require high amplitude, such as nonlinear elastic wave spectroscopy (NEWS) techniques.
134(2013); http://dx.doi.org/10.1121/1.4809774View Description Hide Description
The experimental method employed in an anechoic wind tunnel to characterize flow-induced noise of the pigeon (Columba livia) during level flight is described in this letter. A live pigeon was managed to maintain a steady level flight at the wind tunnel test flow of 15 m/s. A microphone array was fabricated, and the conventional beamforming method was then adopted to yield the corresponding narrowband acoustic images and broadband sound pressure spectral results. The results justified the experimental method developed in this work. It can be seen that the flight noise of the pigeon is mostly from the wing tips. In addition, the spectral waveform of the pigeon flight suggests a slope of −20 dB/dec between 500 Hz and 5 kHz.
134(2013); http://dx.doi.org/10.1121/1.4809772View Description Hide Description
Distortion product otoacoustic emissions (DPOAEs) acquired in normal-hearing subjects show considerable variation in amplitude with varying frequency. This is known as DPOAE fine structure. It is widely accepted that fine structure results from wave interference from two DPOAE sources, a non-linear generation component and a coherent reflection component. Here a method is presented that decomposes short-pulse DPOAE recordings into pulse basis functions and enables the quantification of both source components in the time domain, independent of their relative phase and at low cost of measurement time. Input-output functions utilizing the extracted primary-source component are analyzed.
134(2013); http://dx.doi.org/10.1121/1.4809770View Description Hide Description
This paper proposes a voice activity detection (VAD) method in a kernel subspace domain to improve the performance of the kernel-based VAD. A linear transform matrix that can simultaneously diagonalize the two covariance matrices using kernel principal component analysis is presented to generate the kernel subspace. The likelihood ratio test based on Gaussian distributions is applied for the VAD in the kernel subspace. Experimental results show that the proposed VAD algorithm outperforms the conventional approaches under various noise conditions.
134(2013); http://dx.doi.org/10.1121/1.4809771View Description Hide Description
Previous studies [Tiemann et al., J. Acoust. Soc. Am. 120, 2355–2365 (2006)] have reported the localization of marine mammals in 3-D from their clicks using multipath arrivals. Bathymetric variations were advantageously used to predict multipath arrival times with a raytracer. These arrivals are directly discernible from the time series for impulsive sources, such as whale clicks, but extension of the method to continuous broadband sources presents additional complications. By pulse compressing noise emitted from a small boat using two hydrophones, the hyperbolic direct-arrival ambiguity can be refined in both range and bearing. Acoustic-derived results are validated with target GPS measurements.
Development of a matched filter detector for acoustic signals at local distances from small explosions134(2013); http://dx.doi.org/10.1121/1.4809779View Description Hide Description
A method for acoustic detection of small explosions at local distances is presented combining a matched filter with a p-value representing the conditional probability of detection. Because the physics of signal generation and propagation for small, locally recorded acoustic signals from small explosions is well understood, the single hypothesis to be tested is a signal corrupted by additive noise. A simple analytical signal representation is used where a known signal is assumed with parameters to be determined. The advantage of the approach is that the detector can be combined with other detectors that measure different signal characteristics all under the same unifying hypothesis.
The roles of fundamental frequency contours and sentence context in Mandarin Chinese speech intelligibility134(2013); http://dx.doi.org/10.1121/1.4811159View Description Hide Description
Flattening the fundamental frequency (F 0) contours of Mandarin Chinese sentences reduces their intelligibility in noise but not in quiet. It is unclear, however, how the absence of primary acoustic cue for lexical tones might be compensated with the top-down information of sentence context. In this study, speech intelligibility was evaluated when participants listened to sentences and word lists with or without F 0 variations in quiet and noise. The results showed that sentence context partially explained the unchanged intelligibility of monotonous Chinese sentences in quiet and further indicate that F 0 variations and sentence context act in concert during speech comprehension.
134(2013); http://dx.doi.org/10.1121/1.4811161View Description Hide Description
This study reports a role of temporal regularity on the perception of auditory streams. Listeners were presented with two-tone sequences in an A-B-A-B rhythm that was either regular or had a controlled amount of temporal jitter added independently to each of the B tones. Subjects were asked to report whether they perceived one or two streams. The percentage of trials in which two streams were reported substantially and significantly increased with increasing amounts of temporal jitter. This suggests that temporal predictability may serve as a binding cue during auditory scene analysis.
134(2013); http://dx.doi.org/10.1121/1.4811162View Description Hide Description
An image processing technique called Local Binary Patterns (LBP) has been explored for its ability to generate feature vectors for dolphin vocalization classification. The LBP operator eliminates the need for contour tracing, denoising, and other prior processing. In an experimental study of classifying dolphin whistle types, the performance of the LBP operation was compared with that of the popular contour-based Time-Frequency Parameters (TFP) approach. The preliminary experimental results illustrate that the LBP method produces more consistent classifier accuracy of dolphin whistle calls even when the contour shapes are complex and populated with impulsive clicks and anthropogenic harmonics.
134(2013); http://dx.doi.org/10.1121/1.4809778View Description Hide Description
An analytic means to evaluate the error sensitivity of a personal audio system is proposed. The personal audio system, which focuses acoustic energy into a zone of interest using multiple loudspeakers, is subject to various errors when implemented. The performance of a personal audio system, defined as an energy ratio between the zone of interest and the rest, is inevitably influenced by errors. Thus the ability to predict performance change at the design stage is crucial when building a robust personal audio system. The dependence of the energy ratio change on various types of errors is formulated.
Maintaining intelligibility at high speech intensities: Evidence of lateral inhibition in the lower auditory pathway134(2013); http://dx.doi.org/10.1121/1.4807861View Description Hide Description
Three experiments examined the intelligibility enhancement produced when noise bands flank high intensity narrowband speech. Enhancement was unaffected by noise gating (experiment 1), ruling out peripheral adaptation as a source, and was also unaffected by interaural decorrelation of noise bands flanking diotic speech (experiment 2), indicating that enhancement occurs prior to binaural processing. These results support previous suggestions that intelligibility loss at high intensities is reduced by lateral inhibition in the cochlear nuclei. Results from a final experiment suggest that this effect is only ipsilateral, implicating a specific population of inhibitory neurons.
- LETTERS TO THE EDITOR
Effectiveness of focused source generation methods with consideration of interaural time and level difference134(2013); http://dx.doi.org/10.1121/1.4807825View Description Hide Description
Several methods have been proposed for the generation of the focused source, usually a virtual monopole source positioned in between the loudspeaker array and the listener. The problem of pre-echoes of the common analytical methods has been noticed, and the most concise method to cope with this problem is the angular weight method. In this paper, the interaural time and level difference, which are well related to the localization cues of human auditory systems, will be used to further investigate the effectiveness of the focused source generation methods. It is demonstrated that the combination of angular weight method and the numerical pressure matching method has comparatively better performance in a given reconstructed area.