Volume 121, Issue 2, February 2007
- jasa express letters
- acoustical news—usa
- acoustical news—international
- book reviews
- reviews of acoustical patents
- review articles
- letters to the editor
- general linear acoustics 
- nonlinear acoustics 
- aeroacoustics, atmospheric sound 
- underwater sound 
- ultrasonics, quantum acoustics, and physical effects of sound 
- structural acoustics and vibration 
- noise: its effects and control 
- architectural acoustics 
- acoustic signal processing 
- physiological acoustics 
- psychological acoustics 
- speech production 
- speech perception 
- music and musical instruments 
- bioacoustics 
Index of content:
- JASA EXPRESS LETTERS
121(2007); http://dx.doi.org/10.1121/1.2424264View Description Hide Description
The effect of word order and prosodic focus on the tonal shape and intensity in the production of prosody was studied. The results show that the production of focus in Finnish follows a global pattern with regard to tonal features. The relative pitch height difference between contrasted words is the most important pitch-related factor in signaling narrow prosodic focus. Narrow focus is not localized to prosodically emphasized words only but relates to the utterance as a whole. It was also found that syntactic structure with respect to both intensity and tonal structure modulated relative prosodic prominence of individual words.
121(2007); http://dx.doi.org/10.1121/1.2424266View Description Hide Description
It is well known that the real part of a drive-point function, averaged in frequency, can be estimated from the modal density and mass of a structure. Furthermore, the results are often the same as when the modal overlap is large due to damping or when the system boundaries are infinitely extended. The present Note examines the possible use of modal density in estimating the imaginary part of the same system drive-point function.
121(2007); http://dx.doi.org/10.1121/1.2424267View Description Hide Description
The effect of correlated data errors on matched-field geoacoustic inversion for vertical array data is examined. The correlated errors stem from our inability to model the inhomogeneities in the environment resulting in an additional error term beyond ambient noise. Simulated data with these correlated errors are generated and then inverted with or without using the proper covariance matrix. Results show that the correlated error has a negative impact on geoacoustic parameter estimation if not accounted for properly.
121(2007); http://dx.doi.org/10.1121/1.2430763View Description Hide Description
Mechanical coupling between grains in a randomly packed unconsolidated granular medium is shown to cause an increase in the effective inertia, hence, a reduction in sound and shear wave speeds, relative to predictions by the standard expressions for a uniform elastic solid. The effect may be represented as a virtual mass term, and directly related to the scintillation index of the grain-to-grain contact stiffness.
Loudness pattern-based speech quality evaluation using Bayesian modeling and Markov chain Monte Carlo methods121(2007); http://dx.doi.org/10.1121/1.2430765View Description Hide Description
This work presents a speech quality evaluation method which is based on Moore and Glasberg’s loudnessmodel and Bayesian modeling. In the proposed method, the differences between the loudness patterns of the original and processed speech signals are employed as the observed features for representing speech quality, a Bayesian learning model is exploited as the cognitive model which maps the features into quality scores, and Markov chain Monte Carlo methods are used for the Bayesian computation. The performance of the proposed method was demonstrated through comparisons with the state-of-the-art speech quality evaluation standard, ITU-T P.862, using seven ITU subjective quality databases.
121(2007); http://dx.doi.org/10.1121/1.2430766View Description Hide Description
Modulation-filterbank models discard phase information above very low rates of amplitude modulation (AM). The present work evaluated this restriction by measuring thresholds for discriminating the starting phase of sinusoidal modulators of wideband-noise carriers. Results showed a low-pass characteristic with some listeners unable to perform the task once the modulation rate was greater than . For others, however, thresholds were obtained with AM rates of up to one to two octaves higher. Intersubject variability may in part relate to the presence of multiple discrimination cues, with only some based on comparison of the ongoing pattern of envelope fluctuation.
121(2007); http://dx.doi.org/10.1121/1.2430762View Description Hide Description
Rivenez et al. [J. Acoust. Soc. Am.119 (6), 4027–4040 (2006)] recently demonstrated that an unattended message is able to prime by a simultaneously presented attended message when the two messages have a different range. This study asks whether a difference in vocal-tract length between the two messages rather than a difference in can also produce such priming. A priming effect of was found when messages were in the same range but had different (15%–30%) vocal-tract length, suggesting that the processing of unattended speech strongly relies on the presence of perceptual grouping cues.
121(2007); http://dx.doi.org/10.1121/1.2430764View Description Hide Description
The fluctuation-dissipation theorem is used to show how acoustic Green’s functions corresponding to sound propagation in opposite directions between any two given points can be extracted from time series of thermal noise recorded at these points. The result applies to arbitrarily inhomogeneous, moving or motionless fluids with time-independent parameters, and demonstrates that the two-point correlation function of thermal noise contains as much information about the environment as can be obtained acoustically by placing transceivers at the two points.
- BOOK REVIEWS
- REVIEWS OF ACOUSTICAL PATENTS
121(2007); http://dx.doi.org/10.1121/1.2640062View Description Hide Description
The purpose of these acoustical patent reviews is to provide enough information for a Journal reader to decide whether to seek more information from the patent itself. Any opinions expressed here are those of the reviewers as individuals and are not legal opinions. Printed copies of United States Patents may be ordered at $3.00 each from the Commissioner of Patents and Trademarks, Washington, DC 20231. Patents are available via the Internet at http://www.uspto.gov.
- REVIEW ARTICLES
121(2007); http://dx.doi.org/10.1121/1.2395914View Description Hide Description
Nonlinear internal waves in the ocean are discussed (a) from the standpoint of soliton theory and (b) from the viewpoint of experimental measurements. First, theoretical models for internal solitary waves in the ocean are briefly described. Various nonlinear analytical solutions are treated, commencing with the well-known Boussinesq and Korteweg–de Vries equations. Then certain generalizations are considered, including effects of cubic nonlinearity, Earth’s rotation, cylindrical divergence, dissipation, shear flows, and others. Recent theoretical models for strongly nonlinear internal waves are outlined. Second, examples of experimental evidence for the existence of solitons in the upper ocean are presented; the data include radar and optical images and in situ measurements of wave forms, propagation speeds, and dispersion characteristics. Third, and finally, action of internal solitons on sound wave propagation is discussed. This review paper is intended for researchers from diverse backgrounds, including acousticians, who may not be familiar in detail with soliton theory. Thus, it includes an outline of the basics of soliton theory. At the same time, recent theoretical and observational results are described which can also make this review useful for mainstream oceanographers and theoreticians.
121(2007); http://dx.doi.org/10.1121/1.2404622View Description Hide Description
Although much is known about how speech is produced, and research into speech production has resulted in measured articulatory data, feature systems of different kinds, and numerous models,speech production knowledge is almost totally ignored in current mainstream approaches to automatic speech recognition. Representations of speech production allow simple explanations for many phenomena observed in speech which cannot be easily analyzed from either acoustic signal or phonetic transcription alone. In this article, a survey of a growing body of work in which such representations are used to improve automatic speech recognition is provided.
- LETTERS TO THE EDITOR
Comment on “Analysis of the time-reversal operator for scatterers of finite size,” by D. H.Chambers [J. Acoust. Soc. Am.112, 411–419 (2002)]121(2007); http://dx.doi.org/10.1121/1.2405130View Description Hide Description
This letter concerns the paper “Analysis of the time-reversal operator for scatterers of finite size” [J. Acoust. Soc. Am.112, 411–419 (2002)]. The number of possible eigenvalues and eigenfunctions of the time reversal operator for a finite sphere given in the paper is much more than the correct number, which is proven to be the total number of multipole moments induced inside the finite sphere.
Analysis of voice source characteristics using a constrained polynomial representation of voice source signals121(2007); http://dx.doi.org/10.1121/1.2359234View Description Hide Description
To analyze the characteristics of voice source signals from speech, a model is presented in the form of polynomial function by expanding the definition of the Rosenberg model. In combination with the all-pole assumption of the vocal-tract filter, methods are described for the pitch-synchronous speech analysis and temporal search of the glottal opening and closing instants. Because the source and filter models are both linear, the parameter estimation problem can be conveniently solved. In addition, the temporal search method can refine the locations of the glottal events and improve the accuracy of the parameter estimation. Analyses of non-nasalized voiced speech are conducted using an electroglottographic device from which the initial estimate of the temporal information is given.
121(2007); http://dx.doi.org/10.1121/1.2404922View Description Hide Description
Echolocation clicks from Norwegian killer whales feeding on herring schools were recorded using a four-hydrophone array. The clicks had broadband bimodal frequency spectra with low and high frequency peaks at 24 and , respectively. The bandwidth was . The average source level varied from re (peak-to-peak) @ . This is considerably lower than source levels described for Canadian killer whales foraging on salmon. It is suggested that biosonar clicks of Norwegian killer whales are adapted for localization of prey with high target strength and acute hearing abilities.
- GENERAL LINEAR ACOUSTICS 
121(2007); http://dx.doi.org/10.1121/1.2404931View Description Hide Description
The exact scattering by a sphere centered on a Bessel beam is expressed as a partial wave series involving the scattering angle relative to the beam axis and the conical angle of the wave vector components of the Bessel beam. The sphere is assumed to have isotropic material properties so that the th partial wave amplitude for plane wave scattering is proportional to a known partial-wave coefficient. The scattered partial waves in the Bessel beam case are also proportional to the same partial-wave coefficient but now the weighting factor depends on the properties of the Bessel beam. When the wavenumber-radius product is large, for rigid or soft spheres the scattering is peaked in the backward and forward directions along the beam axis as well as in the direction of the conical angle. These properties are geometrically explained and some symmetry properties are noted. The formulation is also suitable for elastic and fluid spheres. A partial wave expansion of the Bessel beam is noted.
121(2007); http://dx.doi.org/10.1121/1.2405124View Description Hide Description
A fast integral expression for computing the nearfield pressure is derived for axisymmetric radiators. This method replaces the sum of contributions from concentric annuli with an exact double integral that converges much faster than methods that evaluate the Rayleigh-Sommerfeld integral or the generalized King integral. Expressions are derived for plane circular pistons using both continuous wave and pulsed excitations. Several commonly used apodization schemes for the surface velocity distribution are considered, including polynomial functions and a “smooth piston” function. The effect of different apodization functions on the spectral content of the wave field is explored. Quantitative error and time comparisons between the new method, the Rayleigh-Sommerfeld integral, and the generalized King integral are discussed. At all error levels considered, the annular superposition method achieves a speed-up of at least a factor of 4 relative to the point-source method and a factor of 3 relative to the generalized King integral without increasing the computational complexity.
Numerical evaluation of the acoustic radiation from planar structures with general baffle conditions using wavelets121(2007); http://dx.doi.org/10.1121/1.2405125View Description Hide Description
A method is presented for computing the acoustic radiation from baffled, unbaffled, or partially baffled planar structures. The surface displacement and the surfacepressure are expressed in terms of wavelets, and the acoustic dynamic stiffness (baffled case) or the acoustic receptance (unbaffled case) between any two wavelets is derived in closed form. The wavelets are employed with translation only (i.e., no dilation), and the jinc function is used; the Hankel transform of this function is the Heavyside step function, and this feature greatly simplifies the analysis. There is a trivial mapping between the wavelet amplitudes and the physical motion of the structure, and hence the dynamic stiffness and receptance results can readily be used to derive the acoustic dynamic stiffness matrix (by inverting the receptance matrix in the unbaffled case) in any set of generalized coordinates. Partially baffled systems can then be studied by substructuring the dynamic stiffness matrix. A set of example problems is considered in which the method is used to compute the resistive and reactive radiation efficiency of a range of benchmark systems.