bluuebunny/crossref_metadata_2025_split huggingface dataset:
Free-field method for sound-attenuation measurement
Authors: Hruska Gale R. , Koidan Walter 
Published: October 2005

A free-field method is described for measuring the attenuation of sound at ultrasonic frequencies. It makes use of the systematic deviation from the inverse square law caused by attenuation when a sound receiver is drawn away from a sound source. Measurements of attenuation from 20 to 100 kHz, made in air in a small anechoic chamber under ambient environmental conditions, were in good agreement with theoretical calculations. The sum of the distances between the acoustic centers of the transducers and the vibrating elements is obtained as a by-product of the procedure.
Subject Classification: 35.20; 20.35.
Some extensions of Babinet’s principle
Authors: Senior T. B. A. 
Published: October 2005

Two different extensions of Babinet’s principle are discussed. In the first of these, an aperture in a soft or hard screen is covered with a membrane characterized by a jump discontinuity in either the normal component of the fluid velocity or the pressure, and the complementary problem is then a membrane in isolation. In the second, a boundary condition is imposed in the aperture, the solution for which can be obtained from the solution for the complementary disk.
Subject Classification: 20.30.
Short-wavelength acoustic backscattering by a prolate spheroid
Authors: Lauchle Gerald C. 
Published: October 2005

The backscattering of a plane acoustic wave from a rigid prolate spheroid of large fineness ratio (length-to-diameter ratio of 22) is investigated analytically. The backscattering cross section is computed with the use of large argument asymptotic expansions of spheroidal wave functions. It is shown that in the short-wavelength limit, a spheroid backscatters in the axial direction nearly the same mean energy as a sphere whose radius equals the radius of curvature of the spheroid at the pole end. When the spheroid is positioned broadside to the incident wave, the backscattered mean energy is found to correspond to that backscattered from a sphere of diameter equal to the length of the spheroid.
Subject Classification; 20.15, 20.30.
Cross-correlation methods for studying near- and farfield noise characteristics of flow–surface interactions
Authors: Pan Y. S. 
Published: October 2005

Systematic methods based on cross-correlation techniques are presented for experimental studies of near- and farfield noise characteristics in airflow–surface interaction problems. Analyses show that, in near- and farfields, the noise characteristics due to the surface contribution of fluctuating pressures and velocities and due to the volume contribution of the turbulence in the flow can be determined separately. Both farfield noise intensities and nearfield acoustic energy fluxes can be expressed in terms of appropriate cross correlations. These correlations can be obtained by making microphone measurements in the farfield, in the nearfield, and on the surface. Examples of the applications to the noise field generated by impinging jets, by surface blowing jets, and by turbulent flow over trailing edges are presented. Advantages of the present method over conventional methods are also discussed.
Subject Classification: 28.65; 50.25, 50.30, 50.55.
Monaural localization of low-pass noise bands in the horizontal plane
Authors: Belendiuk Krystyna , Butler Robert A. 
Published: October 2005

Monaural localization of low-pass noise positioned in the horizontal plane on the side of the unoccluded ear was investigated. Listeners showed no localizing ability until the upper cutoff frequency of the noise was advanced to 5.0 kHz. Performance proficiency increased progressively with the inclusion of still higher audio frequencies. Consonant with the behavioral data were the results of sound spectrum measurements performed on a head–pinna model. The spectral composition of a broad-band noise positioned at various azimuthal positions became clearly distinguishable, one from another, only at the higher frequencies.
Subject Classification: 65.62, 65.75, 65.54.
Data requirements for the mapping of ultrasonic fields with conventional light diffraction
Authors: Berlinghieri Joel C. , Cook Bill D. 
Published: October 2005

A procedure has been proposed by Cook [J. Acoust. Soc. Am. 53, 330(A) (1972)] through which a cross-sectional mapping of a progressive sound beam could be obtained by conventional light diffraction. This technique requires that a series of optical diffraction measurements be taken laterally across the field, for a large number of rotations about the sound field’s major axis. Since the number of measurements could become excessive, and investigation of the data requirements of this technique has been performed. Computer-generated data were calculated of the integrated optical effect (both magnitude and phase) produced by the pressure field of a circular plane piston in an infinite rigid baffle. From these data a cross-sectional map was obtained using an effective two-dimensional Fourier transform, as well as the two-dimensional fast Fourier transform algorithm. The cross-sectional mapping was evaluated at different axial positions, using one set of data obtained by varying the data set and comparing the results to those obtained from the diffraction integral. The data requirements were found not to be excessive.
Subject Classification: 35.65.
Perturbation solution of the Navier–Stokes equations and its relation to the Lighthill–Curle solution of aerodynamic sound
Authors: Pan Y. S. 
Published: October 2005

The Lighthill–Curle solution of sound generated aerodynamically is examined by a perturbation approach. Based on the method of matched asymptotic expansions, the full Navier–Stokes equations are expanded for a small Mach number. To the first order, the nearfield is generally nonisentropic. The pressure field (pseudosound) is generated by the incompressible Reynolds stresses in the turbulent flow and the velocity, pressure perturbation, and their derivatives on the boundaries. In the farfield, the acoustic field is obtained by matching the nearfield and determined by the first-order sound sources. A uniformly valid first-order solution for the pressure field is obtained. The solution shows that this kind of aerodynamic sound generation does not depend on the viscous, thermal, and entropy effects in the adiabatic flow nor on the shear stress on a rigid smooth boundary. Comparisons with the Lighthill–Curle solution confirm some approximations used in current farfield aerodynamic noise studies.
Subject Classification: 28.65; 30.65; 50.55.
Probe-signal investigation of uncertain-frequency detection
Authors: Macmillan Neil A. , Schwartz Madelyn 
Published: October 2005

Observers in a 2IFC detection task were instructed to listen for ’’primary’’ tones with one of two frequencies, in the presence of a broad-band background noise. On a small proportion of trials, probe tones of other frequencies were presented instead, following the procedure of Greenberg and Larkin [J. Acoust. Soc. Am. 44, 1513–1523 (1968)]. The function relating percent correct to signal frequency may be interpreted as an average internal filter characteristic. All six observers responded correctly on 70%–90% of trials on which primary signals were presented; performance on probe trials was poorer, falling to chance for probe frequencies sufficiently above the higher primary, sufficiently below the lower primary, and for some probes between the two primaries. The widths of the listening bands around the primaries were found to be similar to the widths estimated from one-primary control conditions. Examination of the sequential data suggests that, while the pattern of sensitivity changes from trial to trial, a model postulating a single filter shifting from one primary to the other is not adequate. Other models of uncertain-frequency detection are discussed.
Subject Classification: 65.35, 65.75, 65.58.
Interaural attenuation versus frequency for guinea pig and chinchilla CM response
Authors: Teas Donald C. , Nielsen Donald W. 
Published: October 2005

Interaural attenuation was estimated for the guinea pig and the chinchilla by determining isopotential curves for the cochlear microphonic (CM) response produced by contralateral and by ipsilateral stimulation at frequencies from 300 Hz to 14.3 kHz. Intracochlear electrodes were used to record the CM from the basal turn. For ipsilateral stimulation, bulla-sealed to bulla-open sound pressure ratios showed effects similar to those reported by other investigators: 10–12-dB loss for chinchilla and 20–22-dB loss for the guinea pig for the bulla-sealed condition. The variability of the sound pressure measures, considered across animals, was larger in chinchillas than in guinea pigs, and the variance was greatest at frequencies near those at which the external auditory canals and bulla cavities show resonant peaks. There appears to be additional low-frequency resonances associated with contralateral stimulation for the closed bulla in the chinchilla, largest at 1.1 kHz for frequencies sampled in this report. The interaural attenuation for the chinchilla is largest at low frequencies and is at a minimum of about 34 dB for the open bulla, near 3.0 kHz; in the guinea pig, the minimum interaural attenuation occurs for the closed bulla, about 44 dB at 300 Hz.
Subject Classification: 65.42, 65.40, 65.75.
Range-dependent normal modes in underwater sound propagation: Application to the wedge-shaped ocean
Authors: Graves R. D. , Nagl Anton , Überall H. , Zarur G. L. 
Published: October 2005

We use the adiabatic range variation method of Pierce and Milder to perform an approximate separation into normal modes of the wave equation for the problem of underwater sound propagation in an almost-stratified under-ocean channel with gradual range dependence of medium and boundaries. Our solution is illustrated by an application to the isovelocity ocean wedge with rigid ocean floor, and compared with the exact solution of Bradley and Hudimac. Even when mode coupling is neglected, good agreement is obtained for moderately large wedge angles.
Subject Classification: 30.20; 20.15, 20.40.
Linear estimation of nonstationary signals
Authors: Liporace Louis A. 
Published: October 2005

The efficacy of linear prediction for speech analysis depends upon the degree to which the speech signal is stationary within an analysis interval. For this reason the speech signal is usually divided into small intervals during each of which the signal is assumed to be stationary. The formulation described in this paper is aimed at accomodating the nonstationarity more automatically by allowing the linear estimate of the speech signal to be time varying.
Subject Classification: 70.40, 70.65.
Equivalent circuit of a ceramic ring transducer operated in the dipole mode
Authors: Gordon Robert S. , Parad Leonard , Butler John L. 
Published: October 2005

An equivalent circuit for a piezoelectric ring transducer excited in its dipole mode and its remaining odd-order curcumferential extensional modes is derived. The analysis is accomplished by expressing the applied electric field excitation by a Fourier series and then combining solutions appropriately. The equivalent network presented here has a voltage–current terminal pair and a force–velocity terminal pair to each Fourier component which yield the transducer performance for the dipole and higher-order modes.
Subject Classification: 85.52; 40.85.
Observation of acoustic layering and internal waves with a narrow-beam 87.5-kHz echo sounder
Authors: Fisher F. H. , Squier E. D. 
Published: October 2005

Multiple thin layers have been observed from depths of 154 to 470 m with a narrow-beam (±0.5° at 3 dB down) high resolution (0.6-msec pulse) mounted on the bottom of FLIP. Layer reflection coefficients vary between −90 and −100 dB. The layers varied in depth sinusoidally about 5 m with a 22-min period, indicating internal wave motion. Echo returns from the bottom at 770 fathoms indicated a reflection coefficient of −34 dB, in good agreement with earlier work at 75 kHz by Bezdek.
Subject Classification: 30.20, 30.82.
Nonlinear effects of initial bending on the vibrations of crystal plates
Authors: Lee P. C. Y. , Wang Y. S. , Markenscoff X. 
Published: October 2005

The changes in the resonance frequencies of circular crystal plates subject to initial bending stresses are studied. The plate is flexed as a cantilever clamped near the edge and stressed by a transverse, concentrated force applied at a point diametrically opposite the support. A system of plate equations which takes into account the nonlinear effects due to the large, initial deflection and to the third-order elastic stiffness coefficients in the stress–strain relations is employed. In obtaining the initial fields caused by bending, strain components are assumed to be small, but large gradient of plate deflection and large rotations of the plate element about x1 and x3 axes are permissble by retaining their quadratic terms in the strain-displacement relations. The changes of resonance frequencies of fundamental thickness-shear vibrations are calculated for rotated Y cuts of quartz. The calculated frequency changes are compared with experimental values as a function of the force position, the azimuth angle ψ, and also as a function of the magnitude of thr force P.
Subject Classification :[43]40.24.
Gaussian–Laguerre/Hermite formulation for the nearfield of an ultrasonic transducer
Authors: Cook B. D. , Arnoult W. J. 
Published: October 2005

The orthonormal sets of functions known as Gaussian–Laguerre and Gaussian–Hermite functions (G–L/H) have previously been used in quantum mechanics, electromagnetic waves and laser optics. These functions satisfy a modified wave equation, valid under certain restrictive conditions appropriate to slowly diverging sound fields. The nearfield of an ultrasonic transducer can be expressed as a linear combination of modes, each described by a G–L/H function. Each mode has a slightly different phase velocity in the nearfield but has the same spreading nature and phase velocity in the farfield. Using this formulation, the transition from nearfield to farfield is readily explained.
Subject Classification: [43]20.55; [43]35.80; [43]20.15.
Dichotic ’’masking’’ of voice onset time
Authors: Repp Bruno H. 
Published: October 2005

When CV targets are presented to one ear and isolated vowel masks to the other ear, the perception of the voicing feature of the target is biased by the temporal relationship between target and mask which acts like a ’’pseudo-voice onset time’’ and competes with the actual voice onset time of the target as a voicing cue. The effect is especially strong when there is high a priori uncertainty about the voicing category of the target, and it is more pronounced when the masking vowel lags behind than when it leads in time. The bias is strongest when the masking vowel is the same as the vowel of the target, but is present with a phonetically different vowel mask as well. There tends to be a right-ear advantage which is strongest when the masking vowel leads in time. The fundamental frequency at masking vowel onset has an additional influence: The lower it is, the stronger is the tendency to identify the target as voiced. Two simple additive models of the vowel ’’masking’’ effect are rejected. The relative complexity of the effect suggests dichotic interaction at the phonetic (precategorical) level. The present experiments demonstrate that a temporal relationship, voice onset time, may be ’’masked’’ by another temporal relationship, the voice onset time across ears.
Subject Classification: [43]70.30; [43]65.48, [43]65.58, [43]65.62.
Phase effect of an input f2−f1 tone on the level of the 2f1−f2 combination tone
Authors: Crane Hewitt D. , Bell Donald W. 
Published: October 2005

A model of hair cell excitation that involves mechanical impact between the hair cells and the tectorial membrane has been proposed by Crane [J. Acoust. Soc. Am. 40, 1147–1154 (1966); J. Acoust. Soc. Am. 51, 508–514 (1972)]. The model predicts that if the impact is unilateral, biasing of the basilar membrane toward or away from the tectorial membrane will significantly affect the generation of nonlinear combination tones. An f2−f1 envelope tone synchronized with the f1 and f2 primaries was used to achieve such biasing. The experiment reported here investigates the effect of the phase of the f2−f1 tone on the prominence of the beating of a 2f1−f2 combination tone (generated by input primaries f1 and f2) and a probe tone that differs in frequency by a few hertz from the frequency of the combination tone. The input thus consists of four explicit tones: f1, f2, f2−f1, and (2f1−f2)+δ. It was found that the f2−f1 tone can have a large effect on the level of the 2f1−f2 combination tone. The phases of the f2−f1 tone that lead to a maximum and minimum level of combination tone are approximately 180° apart, and there can be almost total discrimination between those two phase conditions.
Subject Classification: [43]65.56, [43] 65.28, [43]65.60.
Critical angle for reflection at a liquid–solid interface in single crystals
Authors: Henneke Edmund G. , Jones Gerald L. 
Published: October 2005

Recent investigations have utilized the measurement of the critical angle for reflection from a liquid-solid interface for determination of the elastic constants of the solid. For anisotropic media, this technique is appropriate only for certain special cases of the incident plane and reflecting surface. We discuss here the general condition for the critical angel in anisotropic media and show that for some planes in quartz, major errors may arise if one employs the usual statement of Snell’s law for definition of the critical angle.
Subject Classification: [43]20.30; [43]35.26.
Further calculation on Rayleigh wave diffraction by elastic wedges
Authors: Yoneyama Tsukasa , Nishida Shilgeo 
Published: October 2005

An additional calculation is made of diffraction of Rayleigh waves on homogeneous, isotropic elastic wedges following a formulation by Kane and Spence [Geophys. 28, 715–723 (Oct. 1963)]. For the wedges of which interior angles are close to 180°, power transmission, reflection and radiation coefficients can be derived in simple quadratic forms. Numerical data for rapid estimation of these coefficients are presented as functions of Poisson ratio.
Subject Classification: [43]20.30; [43]35.54.
Use of the cepstrum method for arrival times extraction of overlapping signals due to multipath conditions in shallow water
Authors: Fjell Per O. 
Published: October 2005

The use of the cepstrum method for signal arrival times extraction of overlapping signals due to multipath conditions in shallow water is considered. The cepstrum method is applied to signal data from a research cruise. The results fall in two parts: (1) the use of a single cepstrum calculation will not clearly identify the different arrival times and (2) the use of several cepstrum calculations gives a consistant pattern of dominant peaks at or near the calculated arrival times. The assumption made in the cepstrum derivation that echoes are replicas of the first arrival is not correct.
Subject Classification: [43]30.20; [43]60.30; [43]85.84.
Toward damage risk and habitability criteria for pure-tone pulse trains
Authors: Harris J. Donald 
Published: October 2005

Reports from this and other laboratories are summarized to the effect that pulse trains in the 3–4-kHz region, with pulse duration ?1 sec and with on fractions up to 0.05, are habitable when presented a round the clock for weeks, and yield no TTS greater than can be borne, when the level does not exceed 85 dB SPL. For more onerous acoustic loads, a damage risk criterion of 80 dB should be set for long-lasting continuous exposures. The ear is more susceptible to this sort of acoustic load than is any other system of the body, and can serve as an early warning device for potential damage to those systems.
Subject Classification:[43]65.50,[43]65.64, [43]65.66.
Acoustic effects of style of speech
Authors: Ladefoged Peter , Kameny Iris , Brackenridge William 
Published: October 2005

Recordings were made of nine subjects producing test words in seven different styles, varying from completely informal conversation to reading the test words in lists. The subjects were all educated male speakers of standard English who had lived in Southern California from an early age. The data were analyzed using a computer system that determined the frequency, amplitude, and intensity of the first four formants. It was found that the nucleus of the vowel was not affected by differences in the style of speech.
Subject Classification: [43]70.40, [43]70.65.
Comments on ’’Species differences in cochlear fatigue related to acoustics of outer and middle ears of guinea pig and chinchilla’’ [J. Acoust. Soc. Am. 56, 929–934 (1974)]
Authors: Sinyor A. , Laszlo C. A. 
Published: October 2005

There appears to be a significant discrepancy between the results of Drescher and Eldredge [J. Acoust. Soc. Am. 56, 929–934 (1974)] and those reported by Sinyor and Laszlo on the transmission characteristics of the ear canal of the guinea pig. We suggest that this discrepancy is due mainly to the differences in the conditions of the middle ears of the guinea pigs at the time of measurement.
Subject Classification: [43]65.24, [43]65.22.
Use of calculated sound fields and matched-field detection to locate sound sources in shallow water
Authors: Bucker Homer P. 
Published: October 2005

The calculated complex sound field cj for sensor j at depth zj and range rj from a sound source of frequency ω and depth z0 can be written in the normal-mode form as cj= (2π/rj)1/2 ΣmUm(z0) Um(zj) exp[i (kmrj−ωt)]. Here, km is the horizontal wavenumber of mode m and Um is the depth function of the mth mode. It is proposed that the detection factor DF=ΣJj=1 cjc*k〈 (c0jc0k*) *〉 is a reasonable measure for determination of whether a set of sound pressure measurements {c0j} for j=1,2,⋅⋅⋅,J is a good fit to calculated values of {cj} for an assumed location of the sound source. Here 〈 〉 denotes a time average and * denotes complex conjugate. Several examples are shown where a set of {c0j} are calculated for a given source location in a typical shallow water channel and values of DF are then calculated for a grid of range depth or range azimuth locations.
Subject Classification: [43]60.20; [43]30.82.
Nonlinear feedback system for the normalization of active sonar returns
Authors: Ricker Dennis W. 
Published: October 2005

The problem of dynamic range reduction for signal-detection systems operating in the presence of reverberation is discussed. An automatic gain-control system is described that utilizes nonlinear feedback to achieve a high degree of signal envelope normalization over a wide dynamic range. It is shown that the system is characterized by loop dynamics that are insensitive to input level, an improvement over linear, automatic gain-control systems in which loop gain increases with background level which causes increased echo distortion.
Subject Classification: [43]60.30, [43]60.50, [43]30.82, [43]30.40.
New method for normal-mode models of sound propagation in the ocean
Authors: McKisic J. Michael , Hamm D. P. 
Published: October 2005

Newman and Thorson have recently proposed and developed a new method which permits the rapid and efficient solution of eigenvalue problems associated with linear second-order differential equations. Results on applications of the method to problems of interest in underwater acoustics are presented.
Subject Classification: [43]30.20; [43]20.40; [43]30.50.
Quick sound-velocity measurements by an improved pulse-superposition method
Authors: Ishizaki Kozo , Spain Ian L. , Bolsaitis Pedro 
Published: October 2005

This paper discusses a modification of the McSkimin technique which permits measurements on acoustically soft solids of poor quality with a higher accuracy than is possible with the conventional McSkimin technique.
Subject Classification: [43]85.22; [43]35.26, [43]35.80.