Volume 110, Issue 4, October 2001
- acoustical news—usa
- acoustical news—international
- 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 
- structural acoustics and vibration 
- noise: its effects and control 
- architectural acoustics 
- acoustical measurements and instrumentation 
- acoustic signal processing 
- physiological acoustics 
- psychological acoustics 
- speech production 
- speech perception 
- bioacoustics 
Index of content:
- BOOK REVIEWS
110(2001); http://dx.doi.org/10.1121/1.1398047View Description Hide Description
- REVIEWS OF ACOUSTICAL PATENTS
110(2001); http://dx.doi.org/10.1121/1.4736963View 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
110(2001); http://dx.doi.org/10.1121/1.1404975View Description Hide Description
Criteria of depth resolution of interferometric vibration measurements in the cochlea are discussed. Depending on the aim of the measurement, attention should be directed to the outer flank of the interference visibility curve, in contrast to the usual criterion of full width at half maximum. The depth at 30 dB suppression is proposed as a more appropriate criterion, when the measurement site is to be viewed through tissue.
110(2001); http://dx.doi.org/10.1121/1.1398055View Description Hide Description
The Mongolian gerbil is a small rodent with human-like absolute auditory sensitivity in the speech range below 4 kHz. Here, gerbil “speech DLs” (difference limens) are measured along several synthetic speech continua and compared with human data. Results show that gerbils are similar to humans in that they discriminate “within-category” information more easily for vowels than for consonants. However, gerbils are less sensitive to all the speech stimuli, with DLs about 2–3 times higher. Interestingly, gerbil speech DLs are not accurately predicted by their pure-tone frequency DL, which is 36 times that of the human at 1 kHz. Thus, gerbils are actually much more similar to humans in speechsound discrimination than in pure-tone discrimination. It is concluded that the gerbil offers a promising “small-mammal” model for the processing of spectral cues in human speechsounds.
Time-lapse nondestructive assessment of shock wave damage to kidney stones in vitro using micro-computed tomography110(2001); http://dx.doi.org/10.1121/1.1401742View Description Hide Description
To better understand how lithotripter shock waves break kidney stones, we treated human calcium oxalate monohydrate (COM) kidney stones with shock waves from an electrohydraulic lithotripter and tracked the fragmentation of the stones using micro-computed tomography (μCT). A desktop μCT scanning system, with a nominal resolution of 17 μm, was used to record scans of stones at 50-shock wave intervals. Each μCT scan yielded a complete three-dimensional map of the internal structure of the kidney stone. The data were processed to produce either two- or three-dimensional time-lapse images that showed the progression of damage inside the stone and at the surface of the stone. The high quality and excellent resolution of these images made it possible to detect separate patterns of damage suggestive of failure by cavitation and by spall. Nondestructive assessment by μCT holds promise as a means to determine the mechanisms of stone fragmentation in SWL in vitro.
Comment on “Ultrasound-induced lung hemorrhage is not caused by inertial cavitation” [J. Acoust. Soc. Am. 108, 1290–1297 (2000)]110(2001); http://dx.doi.org/10.1121/1.1401758View Description Hide Description
This contribution summarizes the reasons for disagreeing with a conclusion by O’Brien et al. [J. Acoust. Soc. Am. 108, 1290–1297 (2000)] that ultrasound-induced lung hemorrhage is not caused by inertial cavitation. An argument is provided that illustrates how cavitation inception conditions in the lungs of animals are not altered significantly if the hydrostaticpressure is increased by increasing the pressure of air that is being breathed by the animal.
Response to “Comment on ‘Ultrasound-induced lung hemorrhage is not caused by inertial cavitation’ ” [J. Acoust. Soc. Am. 110, 1737 (2001)]110(2001); http://dx.doi.org/10.1121/1.1401759View Description Hide Description
- GENERAL LINEAR ACOUSTICS 
Treatment of frequency-dependent admittance boundary conditions in transient acoustic finite/infinite-element models110(2001); http://dx.doi.org/10.1121/1.1404436View Description Hide Description
The paper addresses the handling of frequency-dependent, local admittance boundary conditions in acoustic transient finite/infinite-element models. The proposed approach avoids the evaluation of a convolution integral along the related boundary. Based on a similar technique developed in an aeroacoustic/finite difference context, the spatially local boundary condition is rewritten in a discrete form that involves normal accelerations and pressure time derivatives at the current time step and few steps before. The incorporation of such a discrete (in time) boundary condition in a finite/infinite-element context is addressed. The infinite-element scheme selected for that purpose relies on the conjugated Astley–Leis formulation. Implementation aspects cover the handling of frequency-dependent boundary conditions along both finite- and infinite-element edges. Numerical examples (waveguide, single source in a half-space bounded by an impedance plane, diffraction by an acoustically treated screen) are presented in order to demonstrate the efficiency of the proposed approach.
110(2001); http://dx.doi.org/10.1121/1.1396330View Description Hide Description
Following our previous attempt at the scattering from a cylinder in a slab to the incidence of a guided shear wave, we hereby discuss the scattering by an elastic cylinder embedded in an isotropic plate for a variety of bonding states to incidence of the fundamental Lamb wave modes and at the low-frequency regime. The plate is divided up into three regions by introducing two imaginary planes located symmetrically some distance from the cylinder and perpendicular to surfaces of the plate. The wave fields in various regions are expanded either into cylinder wave modes or into Lamb wave modes. A system of equations determining the coefficients of expansion is obtained according to the traction-free boundary conditions on the plate walls and the displacement and stress continuity conditions across the virtual planes. By taking an appropriate finite number of terms of the infinite expansion series and some selected points on the two properly chosen imaginary planes and the surfaces of the plate through convergence and precision tests, a matrix equation to numerically evaluate the expansion coefficients is found. Coefficients of the reflection and transmission versus the normalized radius of the cylinder in welded, slip, and cracked interfacial conditions are numerically computed. In the low-frequency range, the relative errors are found to be less than 1%. Contrast curves of the reflection coefficient for the cylinder of nearly all permissible size in perfect and imperfect interfacial bonding are shown and prominent differences are noted.
Leaky helical flexural wave scattering contributions from tilted cylindrical shells: Ray theory and wave-vector anisotropy110(2001); http://dx.doi.org/10.1121/1.1398049View Description Hide Description
At sufficiently high frequencies, cylindrical shells support a wave whose properties are analogous to those of the lowest antisymmetric Lamb wave on plates. When the shell is in water and the frequency exceeds the coincidence frequency, the flexural wave is a leaky wave that can be a major contributor to the scattering by tilted shells [G. Kaduchak, C. M. Wassmuth, and C. M. Loeffler, J. Acoust. Soc. Am. 100, 64–71 (1996)]. While the meridional ray-scattering contributions for such leaky flexural waves were previously modeled, the helical contribution can also be significant. A ray theory for those contributions is compared with the exact partial wave series (PWS) solution for infinitely long empty shells. The agreement between the ray theory and the PWS is only possible when a weak anisotropy of the flexural wave parameters is included in the evaluation of the ray theory. The anisotropy is determined numerically from the roots of a denominator in the PWS because approximations for the anisotropy from thin-shell mechanics are not applicable significantly above the coincidence frequency.
Application of three-dimensional resonant acoustic spectroscopy method to rock and building materials110(2001); http://dx.doi.org/10.1121/1.1402255View Description Hide Description
This paper presents the experimental and theoretical results of applying resonant acoustic spectroscopy (RAS) to determine elastic parameters and losses in such consolidated granular materials as rock and building bricks. First, the theoretical aspects of the RAS method are outlined. A computer code for the rectangular and cylindrical samples was developed and tested. The results of experiments on specimens of rock and ceramic brick are then described. Finally, a modification of the previously published RUS algorithm is presented which permits a significant reduction in computing time for elongated samples.
Near-field scanning in the time domain on a spherical surface— A formulation using the free-space Green’s function110(2001); http://dx.doi.org/10.1121/1.1403698View Description Hide Description
Two formulations for determining the characteristics of an unknown source of acoustic waves using the measurement of its field at its near zone are presented. The measurement in both cases is to be performed on a spherical scan surface which encapsulates the source. The first is for an ideal probe which measures the field at its location. The knowledge of the field is sufficient; its normal derivative is not required. In the second formulation a realistic probe is considered. This time it is required only that the probe has an axially symmetric receiving characteristic. With this formulation, the time functions which characterize the source are found using only the signal at the output of the probe. Both formulations are such that they are not specific to the scan surface radius. Furthermore, they are entirely in the time domain, requiring no inverse Fourier transformations left to be performed.