Volume 113, Issue 1, January 2003
- acoustical news—usa
- book reviews
- reviews of acoustical patents
- letters to the editor
- general linear acoustics 
- nonlinear acoustics 
- aeroacoustics, atmospheric sound 
- underwater sound 
- ultrasonics, quantum acoustics, and physical effects of sound 
- transduction 
- structural acoustics and vibration 
- noise: its effects and control 
- acoustic signal processing 
- physiological acoustics 
- psychological acoustics 
- speech production 
- speech perception 
- music and musical instruments 
- bioacoustics 
Index of content:
- ACOUSTICAL NEWS—USA
- BOOK REVIEWS
- REVIEWS OF ACOUSTICAL PATENTS
113(2003); http://dx.doi.org/10.1121/1.1529213View 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.
- LETTERS TO THE EDITOR
Virtual error sensing for active noise control in a one-dimensional waveguide: Performance prediction versus measurement (L)113(2003); http://dx.doi.org/10.1121/1.1523386View Description Hide Description
Virtual error sensing is a novel active noise control technique, which is designed to produce a zone of attenuation remote from the physical error sensors. In this letter virtual sensing is investigated for tonal noise (both on and off resonance) in a long narrow duct. The performance of the virtual error sensors using real-time control is compared to the performance determined from an analytical model and the performance determined through the postprocessing of experimental data. Two examples of control using postprocessed experimental transfer function data are presented; the first relied on transfer functions measured using broadband noise and the second relied on transfer functions measured at discrete frequencies. The results highlight the significant errors encountered as a result of using broadband transfer functions in lightly damped enclosures.
Laboratory measurements of sound scattering from a buried sphere above and below the critical angle (L)113(2003); http://dx.doi.org/10.1121/1.1523310View Description Hide Description
Laboratory measurements of low frequency (1–10 kHz) evanescent wave field scattering from a sphere buried in water-saturated sand was examined. A 60 cm stainless steel sphere was buried just below a sand–water interface and the acoustic backscattering cross section was measured for above and below critical angle geometries. The below critical angle insonification results clearly show significant levels of backscatter from the buried sphere due to evanescent wave insonification at the lower end of the spectrum (1–3.5 kHz). These measurements compare favorably with first principle estimates of the backscattered target strength and with a T-matrix-based numerical model.
Comment on “Development of panel loudspeaker system: Design, evaluation and enhancement” [J. Acoust Soc. Am. 106, 2751–2761 (2001)] (L)113(2003); http://dx.doi.org/10.1121/1.1526495View Description Hide Description
This letter concerns the paper “Development of panel loudspeaker system: Design, evaluation and enhancement” [M. R. Bai and T. Huang, J. Acoust. Soc. Am. 109, 2751–2761 (2001)]. It is suggested that the radiation field generated by the near vibration field induced by a point force acting on the plate has been neglected. It is pointed out that its relative contribution is crucially dependent upon the mechanical loss factor of the panel, for which no data are presented. The conclusion that the radiated power per unit mean square force is independent of frequency neglects the radiation efficiency factor. Other perceived shortcomings of the paper are noted.
113(2003); http://dx.doi.org/10.1121/1.1513799View Description Hide Description
Measurements of acoustic and vibration background noise were made on 18 September 2001 at the southern edge of the World Trade Center collapse. Sensors were deployed in a configuration reasonable for survivor search and near an on-going recovery operation and heavy debris removal. Geophones were placed on steel beams that extended into a deep void and a microphone was lowered below ground level into a pocket in the rubble. Even in what appeared at ground level to be a high-noise environment, weak or distant taps and bangs generated either by the authors or by recovery personnel produced distinct signals from the microphone and geophones.
The role of envelope beat cues in the detection and discrimination of second-order amplitude modulation (L)113(2003); http://dx.doi.org/10.1121/1.1523383View Description Hide Description
The present study extends previous work from Lorenzi et al. [J. Acoust. Soc. Am. 110, 2470–2478 (2001)] by investigating the respective contribution of two temporal cues (fast modulation sideband and slow envelope beat cues) to the detection and discrimination of “second-order” sinusoidal amplitude modulation (SAM). Second-order SAM detection and rate discrimination abilities were measured at low beat rates Hz) with a “carrier” modulation rate fixed at a high value Hz). The second-order SAM data were compared with first-order SAM detection and rate discrimination thresholds measured in similar conditions at rates between 1 and 256 Hz. The results showed that (1) through 64 Hz, first- and second-order SAM detection thresholds increased similarly when stimulus duration decreased from 2 s to 250 ms, whereas first-order SAM detection thresholds remained unaffected by changes in duration when Hz, and (2) through 32 Hz, first- and second-order SAM rate discrimination thresholds were similar and substantially lower than first-order SAM rate discrimination thresholds measured at Hz. These data demonstrate that the perception of second-order SAM is mainly based on the slow envelope beat cues. They also suggest a substantial contribution of the slow envelope beat cues appearing at the output of modulation filters tuned to or near to the perception of second-order SAM.
113(2003); http://dx.doi.org/10.1121/1.1527959View Description Hide Description
Recently, Holt and Lotto [Hear. Res. 167, 156–169 (2002)] reported that preceding speech sounds can influence phonetic identification of a target syllable even when the context sounds are presented to the opposite ear or when there is a long intervening silence. These results led them to conclude that phonetic context effects are mostly due to nonperipheral auditory interactions. In the present paper, similar presentation manipulations were made with nonspeech context sounds. The results agree qualitatively with the results for speech contexts. Taken together, these findings suggest that the same nonperipheral mechanisms may be responsible for effects of both speech and nonspeech context on phonetic identification.
113(2003); http://dx.doi.org/10.1121/1.1528931View Description Hide Description
Recordings were made of the sounds produced by white whales during capture events in Storfjorden, Svalbard, in the late autumn. Only four of eight captured individuals produced sounds. Four subadults, one female and three males, between 330 and 375 cm long, did not produce sounds during handling. The four animals that produced sounds were as follows: a female subadult of 280 cm produced repetitive broadband clicks; a solitary calf produced harmonic sounds, which we suggest may serve as mother–calf “contact calls,” and a mother–calf pair were the two animals that produced the most sounds in the study. The mother produced “crooning” broadband clicks and frequently moved her head toward her calf while producing underwater sounds. The calf produced three types of frequency-modulated sounds interspersed within broadband click trains. No sounds were heard from any of the animals once they were free-swimming, or during ad lib recording sessions in the study area, even though groups of white whales were sighted on several occasions away from the capture net.
- GENERAL LINEAR ACOUSTICS 
113(2003); http://dx.doi.org/10.1121/1.1528592View Description Hide Description
This paper provides a temporal model of the direct and inverse scattering problem for the propagation of transient ultrasonicwaves in a homogeneous isotropic slab of porous material having a rigid frame. This new time domain model of wave propagation takes into account the viscous and thermal losses of the medium as described by the model of Johnson et al. [D. L. Johnson, J. Koplik, and R. Dashen, J. Fluid. Mech. 176, 379 (1987)] and Allard [J. F. Allard (Chapman and Hall, London, 1993)] modified by a fractional calculus based method applied in the time domain. This paper is devoted to the analytical calculus of acoustic field in a slab of porous material. The main result is the derivation of the expression of the scattering operators (reflection and transmission) which are the responses of the medium to an incident acoustic pulse. In this model the reflection operator is the sum of two contributions: the first interface and the bulk of the medium. Experimental and numerical results are given as a validation of our model.
113(2003); http://dx.doi.org/10.1121/1.1523081View Description Hide Description
Fourier analysis and normal mode theory are used to describe the reflection of bounded inhomogeneous waves on a liquid/solid interface. Nonspecular reflection phenomena in the Rayleigh angle are studied in detail. In this way, an explanation is given for the Rayleigh dip phenomenon for positive inhomogeneity factors and the related result of a reflection coefficient larger than unity when the sign of the inhomogeneity factor is reversed. In the limit of large beamwidths, the reflection coefficient predicted by the infinite plane inhomogeneous wave theory is obtained. These results are entirely consistent with the experimental work published by Deschamps [J. Acoust. Soc. Am. 96, 2841–2848 (1994)]. The energy efficiency of Rayleigh wave excitation is investigated as well. It is shown that for large beamwidths, the energy efficiency for bounded inhomogeneous waves is considerably higher in comparison with Gaussian and square-profiled beams.
Experimental demonstration of noninvasive transskull adaptive focusing based on prior computed tomography scans113(2003); http://dx.doi.org/10.1121/1.1529663View Description Hide Description
Developing minimally invasive brain surgery by high-intensity focused ultrasound beams is of great interest in cancer therapy. However, the skull induces strong aberrations both in phase and amplitude, resulting in a severe degradation of the beam shape. Thus, an efficient braintumor therapy would require an adaptive focusing, taking into account the effects of the skull. In this paper, we will show that the acoustic properties of the skull can be deduced from high resolution CT scans and used to achieve a noninvasive adaptive focusing. Simulations have been performed with a full 3-D finite differences code, taking into account all the heterogeneities inside the skull. The set of signals to be emitted in order to focus through the skull can thus be computed. The complete adaptive focusing procedure based on prior CT scans has been experimentally validated. This could have promising applications in braintumor hyperthermia but also in transcranial ultrasonic imaging.
Scattering from a single bubble near a roughened air–water interface: Laboratory measurements and modeling113(2003); http://dx.doi.org/10.1121/1.1519543View Description Hide Description
The problem of scattering from a single bubble located close to a slightly roughened, air–water interface is studied both theoretically and experimentally. Two well-controlled laboratory experiments were performed to investigate the effects of surface roughness on the scattering response of the bubble. In the first experiment, a bubble of radius 1200 μm was placed on a fine thread at a variable distance, d, from the mean-still-water level of the surface, which was roughened using a wind source. In the second experiment, a bubble of radius 800 μm was utilized, while the water surface was roughened using a plunger wave-making source. The waveheights and important characteristic length scales associated with each experiment were quantified using digital photography. The wind source produced waveheights that were represented by a Gaussian distribution, while the plunger source produced waveheights that were represented by a bimodal distribution. To model the acoustic measurements, an expression describing the four scattering paths, from source to bubble to receiver, was used. A random phase shift due to the surface roughness was added to the paths that interacted with the surface, and expectations of this phase shift were computed based on the analytical representations for the waveheight distribution. The data show good agreement with the simulations and the sensitivity of scattering from a subsurface bubble to small changes in waveheight is illustrated. The experiments highlight important parametric dependencies, which are summarized here, and the relation between monostatic and bistatic scattering is also discussed.
Circumferential resonance modes of solid elastic cylinders excited by obliquely incident acoustic waves113(2003); http://dx.doi.org/10.1121/1.1525289View Description Hide Description
When an immersed solid elastic cylinder is insonified by an obliquely incident plane acoustic wave, some of the resonance modes of the cylinder are excited. These modes are directly related to the incidence angle of the insonifying wave. In this paper, the circumferential resonance modes of such immersed elastic cylinders are studied over a large range of incidence angles and frequencies and physical explanations are presented for singular features of the frequency-incidence angle plots. These features include the pairing of one axially guided mode with each transverse whispering gallery mode, the appearance of an anomalous pseudo-Rayleigh in the cylinder at incidence angles greater than the Rayleigh angle, and distortional effects of the longitudinal whispering gallery modes on the entire resonance spectrum of the cylinder. The physical explanations are derived from ResonanceScattering Theory (RST), which is employed to determine the interior displacement field of the cylinder and its dependence on insonification angle.
113(2003); http://dx.doi.org/10.1121/1.1529668View Description Hide Description
Whereas standard boundary element calculations focus on the forward problem of computing the radiated acoustic field from a vibrating structure, the aim in this work is to reverse the process, i.e., to determine vibration from acoustic field data. This inverse problem is brought on a form suited for solution by means of an inverse boundary element method. Since the numerical treatment of the inverse source reconstruction results in a discrete ill-posed problem, regularization is imposed to avoid unstable solutions dominated by errors. In the present work the emphasis is on Tikhonov regularization and parameter-choice methods not requiring an error-norm estimate for choosing the right amount of regularization. Several parameter-choice strategies have been presented lately, but it still remains to be seen how well these can handle industrial applications with real measurement data. In the present work it is demonstrated that the L-curve criterion is robust with respect to the errors in a real measurement situation. In particular, it is shown that the L-curve criterion is superior to the more conventional generalized cross-validation (GCV) approach for the present tire noise studies.
Inverse estimation of the acoustic impedance of a porous woven hose from measured transmission coefficients113(2003); http://dx.doi.org/10.1121/1.1526664View Description Hide Description
A porous tube, comprised of a resin-coated woven fabric has recently been used as an effective component for use in intake systems of internal combustion engines to reduce the intake noise. For the prediction of the acoustic performance of an engine intake system with a porous woven hose, the acoustic wall impedance of the hose must be known. However, the accurate measurement of the wall impedance of a porous woven hose is not easy because of its peculiar acoustical and structural characteristics. A new measurement technique is proposed herein, that is valid over the low to mid frequency ranges. The acoustics impedance is inversely estimated from an overdetermined set of measured pressure transmission coefficients for specimens of different lengths and the reflection coefficient of end termination. The method involves only one measurement setup, and, as a result, it is very simple. A variation of the proposed method, an inverse estimation method using one of the four-pole parameters is also proposed. An error sensitivity analysis was performed to investigate the effect of measurement error on the accuracy of the final result. The measured TL for samples with arbitrary lengths and arbitrary porous frequency are in reasonably good agreement with values predicted from curve-fitted impedance data.
- NONLINEAR ACOUSTICS 
113(2003); http://dx.doi.org/10.1121/1.1528926View Description Hide Description
A computationally efficient model capable of simulating finite-amplitude ultrasound beam propagation in water and in tissue from phased linear arrays and other transducers of arbitrary quasiplanar geometry is described. It is based on a second-order operator splitting approach [Tavakkoli et al., J. Acoust. Soc. Am. 104, 2061–2072 (1998)], with a fractional step-marching scheme, whereby the effects of diffraction, attenuation, and nonlinearity can be computed independently over incremental steps. This approach is an extension to that of Christopher and Parker [J. Acoust. Soc. Am. 90, 507–521; 90, 488–499 (1991)], wherein linear and nonlinear effects are propagated separately over incremental steps, and the computation of the diffractive substeps are based on an angular spectrum technique with a modified sampling scheme for accurate and efficient implementation of diffractive propagation from nonradially symmetric sources. Results of the model are compared with published data. Predicted field profiles for nonlinear propagation in tissue from realistic array transducers using the pulse inversion method are presented.