bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental observations of a mechanical cochlear model
Authors: Chadwick R. S. , Adler D. 
Published: October 2005

A two-chamber cochlear model was built with the basilar membrane modeled by a thin elastic beam. For various input frequencies the steady-state envelopes of the beam oscillations were measured using several combinations of elastic beams and viscous fluids. The frequency dependence of the thickness of the periodic boundary layer adjacent to the beam was also determined. The experimental results are in general agreement with theoretical predictions, and the ability of viscous damping to alter the shape of the envelopes is confirmed. An optical lever suitable for measuring relatively small displacements is also described.
Subject Classification: 65.26, 65.35.
Underwater localization of pulsed pure tones by the California sea lion (Z
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Authors: Moore Patrick W. B. , Au Whitlow W. L. 
Published: October 2005

The results of a study to determine the pulsed pure-tone sound-localization capability of a California sea lion, Zalophus californianus, in the horizontal plane are presented. The minimum audible angle (MAA) was determined as a function of frequency from 0.5 to 16 kHz in 1-octave steps. The results suggested that the animal utilized time-difference cues for the lower frequencies (0.5 to 1.0 kHz) and intensity-difference cues for the higher frequencies (4.0 to 16.0 kHz). The MAAs for the lower frequencies were smaller than for the higher frequencies, and for the transitional frequencies (2.0 to 4.0 kHz) the animal experienced extreme difficulties in localizing the sound. To further investigate the effects of sound intensity difference in the localization process, an experiment using a sea lion skull with hydrophones attached close to each bulla was conducted. Intensity differences were measured with the skull directed at different azimuths in relatioship to a sound source. The results of the measurements using the skull considered together with the behavioral data support the contention that the sea lion used both time and intensity cues for underwater localization.
Subject Classification: 65.62; 80.50.
Low-frequency phase distortion of speech recordings
Authors: Holmes J. N. 
Published: October 2005

Low-frequency phase distortion introduced by good quality audio tape recorders causes large errors in the reproduced waveform. It is advocated that a low-frequency rectangular wave should always precede the speech on recordings intended for wide distribution, so that the correct phase relationships of spectrum components can be identified. Examples of phase correction by backwards filtering with a sampled-data filter are given. In the absence of a calibration signal, one example used knowledge of typical glottal pulse shapes as a guide for phase correction.
Subject Classification: XX.XX.
Extensional vibration of thin plates of various shapes
Authors: Chen Stanley S. H. , Liu Ta Ming 
Published: October 2005

The problem of free extensional (in plane) vibration of thin plates of Hookean material of various shapes was studied. Solutions for dilatational and rotational vibrations were obtained separately. The boundary conditions were satisfied in a least-square sense. Numerical computations were performed for circular, elliptical, triangular, square, and hexagonal plates. The nodal pattern corresponding to each natural frequency for different modes was obtained. The frequency parameters computed for the circular plate are found to be within 0.05% of published results. For plates where known results were not available, the accuracy was checked by taking additional terms in the series solution and by dividing the boundary perimeter into finer intervals. It was found that the circular plate had the lowest fundamental frequency (k1) at 2.049. The value increases as the shape is changed from a circle, with the triangular plate having the highest value at 6.733 in dilatational vibration while the frequencies in rotational vibration (h1) were found to be 3.737 and 16.364, respectively.
Subject Classification: 40.24.
Transmissibility across simply supported thin plates. I. Rectangular and square plates with and without damping layers
Authors: Ochs J. B. , Snowdon J. C. 
Published: October 2005

The transmissibility across thin, simply supported, rectangular, and square aluminum plates has been determined experimentally and found to agree closely with theoretical prediction through the frequency range of measurement, which extended from 25 to 3025 Hz. Both the rectangular and the square plates considered were uniquely supported by spring-steel flanges, which were designed to provide, for the first time, true simple supports that simulated almost identically the idealized supports assumed as boundary conditions in theoretical analyses for more than a century. For example, the first 20 resonant frequencies of the rectangular plate with these novel supports differed, with only one exception, by less than 0.55% from their predicted values. One important result obtained for the damped plates considered—which comprised aluminum plates plus applied tiles of high-damping compound to yield composite plates having damping factors of essentially 0.3—was that the measured transmissibility across the plates could be duplicated closely by an expression for transmissibility developed for an internally damped homogeneous plate having damping factors equal to those of the composite plates.
Subject Classification: 40.24, 40.60, 40.20.
Vibrating modes for simply supported polar-orthotropic sector plates
Authors: Rubin C. 
Published: October 2005

A method is shown which will provide natural frequencies and mode shapes for the free vibrations of a simply supported polar orthotropic sectorial plate. The special case of a wedge-shaped plate is also treated. The solution applies to any sectorial plate with radial edges simply supported and arbitrary boundary conditions along the circular edges. A series solution which converges rapidly for many natural frequencies is obtained for radial, circular, and mixed modes. An evaluation of the affect of plate orthotropy on the modes is presented. The solution is easily reduced to the isotropic case.
Subject Classification: 40.24.
Intelligibility of speech under nonexponential decay conditions
Authors: Yegnanarayana B. , Ramakrishna B. S. 
Published: October 2005

In this paper, subjective studies made on nonexponentially decaying sounds are described. The various decay conditions are realized by changing the position of the pickup microphone in a reverberation room with a highly absorbing sample on the floor. It is shown, by means of articulation tests, that intelligibility of speech is more close to a highly absorbing sample than away from it. It is also shown that the perception of decay is mainly due to the initial portion of a nonexponential decay. The significance of these studies is determining the acoustics of halls is explained.
Subject Classification: 55.20; 70.35; 55.30.
Cochlear nerve fiber responses: Distribution along the cochlear partition
Authors: Pfeiffer Russell R. , Kim Duck O. 
Published: October 2005

Fourier analysis of discharge patterns in response to sinusoidal acoustic stimulation provides a consistent and repeatable measure of response phase and amplitude. The distribution of the fundamental components of response for large populations of fibers as a function of their characteristic frequency provides a link between the spatiotemporal characteristics of basilar membrane vibration and single fiber response.
Subject Classification: 65.42, 65.40.
Convenient system for precise ultrasonic measurements using the time-interval-averaging method
Authors: Kondo Ken-ichi , Itoh Kiyoshi , Sawaoka Akira , Saito Shinroku 
Published: October 2005

A convenient system for ultrasonic measurements has been developed by using the time interval averaging (TIA) method. Since a standard type of universal counter with TIA circuit can be used, the system consists of simple and low-priced equipment. The sensitivity for relative changes in travel time of ultrasonic waves is better than 0.4 nsec. The travel time is automatically shown on the counter withount any manual adjustment.
Subject Classification: 85.22; 35.24, 35.80.
Scattering of obliquely incident plane acoustic waves by an elastic disk
Authors: Knittel Max R. , Nichols Charles S. , Barach Don 
Published: October 2005

In a previous paper, the authors developed a formulation for mathematically modeling the scattering of plane acoustic waves by an elastic body, and results were presented for the scattering of normally incident plane waves from a disk. In this paper, results are presented for scattering of obliquely incident plane waves from the same disk. Total scattering cross sections are calculated as functions of frequency and incident angle. For an incident wave angle of 60°, the calculated displacement distributions on the disk are decomposed into the disk’s free vibrational eigenmodes at selected frequencies. The scattering patterns of total pressure and of scattered pressure and contour plots of the nearfield pressure distributions are also presented for frequencies of interest.
Subject Classification: 30.35, 30.40, 30.30.
Determination of the wave velocity in an inhomogeneous medium from the reflection coefficient
Authors: Razavy M. 
Published: October 2005

In this paper, we study the problem of obtaining the velocity of the wave propagation in an inhomogeneous medium from the reflection coefficient (given for all frequencies) for a one-dimensional wave equation. Following the work of Kay and Moses, we reduce the problem to that of determining a ’’potential’’ for a Schrödinger-type equation. However, in our work this ’’potential’’ depends quadratically on the wavenumber, and this dependence changes the structure of the spectral function and integral equations of the inverse problem. In the first part of the paper, we assume that the wave velocity c (x) has the same value at x=+∞ and at x=−∞. Then we relax this condition on c (x) and consider the cases where c (+∞) is different from c (−∞), but both quantities have well-defined values. For certain types of velocities, we obtain the reflection coefficient analytically. We then use these reflection coefficients to get approximate solutions to the inverse problem. Finally, we present an example of a heterogeneous medium which is transparent for all frequencies of the incident wave.
Subject Classification: 20.30, 20.35, 20.15.
Laser-excited broadside array generated from a spherically spreading laser beam
Authors: Larson Richard S. 
Published: October 2005

The problem of the generation of sound from an intensity-modulated laser is generalized to include the effect of spherical spreading of the propagating laser beam. It is shown that divergence of the laser beam reduces the sound generated perpendicular to the axis of the laser beam and increases the beam width of the sound wave.
Subject Classification: 35.65.
Incoherent ultrasonic imaging system
Authors: Sato Takuso , Wadaka Shusou 
Published: October 2005

Fundamental construction and some experimental results of incoherent ultrasonic imaging systems are presented. A means for the generation of incoherent ultrasonic fields, a proper scanning method of receivers for the detection of coherence functions, and methods of signal processing for the reconstruction of images from the detected coherence functions are proposed and their properties are discussed theoretically. A concrete system based on these discussions is constructed. The experimental results show the usefulness of the proposed system, though the experiments are carried out only for one-dimensional objects. Moreover, as an example for showing the special feature of the system, it is applied to imaging in a turbulent medium. The effectiveness of the method is illustrated by comparing the result with that of a holographic imaging system.
Subject Classification: 35.65; 60.30.
Bearing estimation using a large towed array
Authors: Hinich Melvin J. , Rule William 
Published: October 2005

When a towed array of hydrophones is significantly nonlinear due to bending, ordinary linear array beamforming gives a biased estimate of the true source bearing. By processing the array as a sequence of smaller aperture subarrays and then computing the mean of the subarray bearings, the variation due to bending is reduced and a reasonably precise estimate is obtained if the average bending angle with respect to the nominal axis is small. The median and mean subarray bearings are analyzed for a theoretical statistical model and are tested using artificial data for various sinusoidal array geometries.
Subject Classification: 60.20; 30.82.
Synthetic whole-nerve action potentials for the cat
Authors: de Boer E. 
Published: October 2005

In response to a tone burst, a pattern of activity is set up in the set of auditory nerve fibers. A simplified model is described in this paper that can represent this pattern both with respect to the number of nerve fibers involved and the detailed time course of the firings. The parameters of the model concerning frequency selectivity and latency are adapted from measurements with the so-called reverse correlation technique. Further properties incorporated in the model are saturation for excitation over 40 dB above threshold and high sensitivity. When specific assumptions are made regarding the contribution of the firing of each nerve fiber to the whole-nerve potential, the waveform of the action potential (AP) can be synthesized from the model. The theory gives a quantitative account of the dependence of the AP latency upon stimulus intensity. Two main contributing factors are frequency selectivity and latency distribution of nerve fibers. Experimental AP amplitudes show a more complex course as a function of stimulus intensity than the theory predicts. Several possible improvements of the method are discussed. Since AP recordings are often used for diagnostic purposes, a separate section of the paper is dedicated to the connection between the properties of auditory nerve fibers and of the whole-nerve AP in abnormal ears.
Subject Classification: 65.42, 65.35.
Nonmonotonic behavior of distortion product 2f1−f2: Psychophysical observations
Authors: Hall J. L. 
Published: October 2005

A detailed study was made of the amplitude and phase characteristics of auditory distortion product 2f1−f2 in the neighborhood of an amplitude minimum. For f2=1.0, 1.2, and 1.4 kHz, f1 was varied from 0.68⋅f2 to 0.88⋅f2, and the (equal) intensity of the two primary tones was varied from 50 to 70 dB SPL. For the one subject investigated, the ampltiude of the 2f1−f2 distortion product exhibited a single minimum in the portion of the f1/f2 versus intensity plane explored. The value of f1/f2 at the minimum was 0.8 and was roughly constant for various frequencies of f2. The primary-tone amplitude at the minimum decreased with increasing f2 from 60 dB SPL at 1 kHz to less than 50 dB SPL at 1.4 kHz. The 2f1−f2 phase in the neighborhood of the null was complicated. It changed abruptly at the minimum, it changed more rapidly with f1/f2 at primary-tone intensities below the null than above, and it changed slowly with primary-tone intensity at f1/f2 ratios both below and above the null. Therefore, a complete circuit around the null in the f1/f2 versus intensity plane resulted in a change of 2f1−f2 phase of 360°.
Subject Classification: 65.56.
Comments on ’’Radial vibrations of axially polarized piezoelectric ceramic cylinders’’ [N. T. Adelman, Y. Stavsky, and E. Segal, J. Acoust. Soc. Am. 57, 356–360 (1975)]
Authors: Onoe Morio 
Published: October 2005

Attention is called to a previous work done by the author in 1963. An explicit formula for electrical admittance and the piezoelectric excitation of even-numbered overtone modes of vibration are quoted.
Subject Classification: 40.26; 85.52.
Reply to ’’Comments on ’Radial vibrations of axially polarized piezoelectric ceramic cylinders’ ’’ [M. Onoe, J. Acoust. Soc. Am. 58, 1099(L) (1975)]
Authors: Adelman N. T. , Stavsky Y. , Segal E. 
Published: October 2005

The authors reply to comments by M. Onoe.
Subject Classification: 40.26; 85.52.
Static acoustic impedance of the chinchilla middle ear: Awake and sedated
Authors: Woodford Charles M. , Henderson Donald , Hamernik Roger P. , Feldman Alan S. 
Published: October 2005

The static acoustic impedance of the chinchilla ear was measured in 50 animals, using the Grason–Stadler model 1720 Otoadmittance meter. The mean acoustic impedance in the awake animal was found to be 747 acoustic ohms. The standard deviation was 171 acoustic ohms. Acoustic impedance measures were obtained under the influence of various doses of Diabutal. The results indicate that there in an increase in negative pressure in the middle ear and concommitant decrease in acoustic impedance following administration of this anesthetic. The magnitude of the change in acoustic impedance was dependent upon the dosage administered. In addition, various aspects of the chinchilla tympanogram are discussed.
Subject Classification: 65.24, 65.22.
History and present status of liquid surface acoustical holography
Authors: Brenden Byron B. 
Published: October 2005

Use of the liquid surface as a detector of ultrasonic energy dates back to 1935. Its use as a detector in acoustical holography began early in 1964. The dynamic response of the liquid surface permits real-time viewing of the image at frame rates of more than 100 per second. Color translation has been demonstrated but is not currently being used in practical systems. Images of soft tissue structures in the hand, arm, and in excised organs show much interesting and useful detail including tendons, muscles, tendon attachments to the skeletal structure, veins, and arteries.
Subject Classification: 10.60; 35.65.
Comments on ’’Measured jet noise compared to California noise codes and health limits’’ [S. R. Lane, J. Acoust. Soc. Am. 56, 1805–1810 (1974)]
Authors: Hildebrand B. G. 
Published: October 2005

In this paper on jet noise measurements the author claims that noise measurements he made under aircraft approach paths to Los Angeles International Airport, and noise measured by Hydrospace Research Corporation and the City of Inglewood, California, show that airplane noise consistently exceeds SENEL limits of the California Noise Rule. The author’s SENEL values were estimated by adding ’’appropriate factors’’ to dBA meter readings. He drew an erroneous conclusion from the Hydrospace and the Inglewood data as a result of extrapolating noise levels specified by the California Noise Rule to large distances. Contrary to his belief, the Hydrospace and Inglewood data show that airplanes do not consistently violate the California Noise Rule. Lane’s reported results do not agree with results reported in similar tests conducted by The Boeing Company, Hydrospace Research Corporation, or the City of Inglewood.
Subject Classification: 50.50, 50.75, 50.55.
Finite-amplitude standing waves within real cavities
Authors: Coppens Alan B. , Sanders James V. 
Published: October 2005

A three-dimensional mathematical model for acoustical standing waves in lossy fluid-filled cavities has been obtained which requires empirical values for the resonance frequencies fn and quality factors Qn (all measured in the linear acoustic régime) of the pertinent standing waves which the cavity can support. The nonlinear distortion of the observed pressure waveform depends strongly on the f’s and Q’s of those standing waves excited by harmonics of the driving frequency. The model is applicable to nonideal cavities if the deviations from idealized geometry and boundary conditions are small. It is restricted to small values of M (1+1/2 B/A) Q1 where M is the peak Mach number and Q1 the quality factor of the fundamental component of the driven standing wave, and B/A is the parameter of nonlinearity of the fluid. Comparisons between the model and experiment are made for a rectangular cavity driven in one- and two-dimensional modes. Agreement is excellent except when there are degeneracies involving the predicted nonlinearly excited standing waves and other standing waves of the cavity. Small discrepancies appear to result from the coupling of energy from the nonlinearly excited standing wave into its degenerate neighbor.
Subject Classification: 25.25; 55.20.
Measurement of freeway noise and community response
Authors: Jenkins M. A. , Pahl Juergen 
Published: October 2005

Personal interviews were conducted with 562 freeway-proximal residents and 134 residents in control neighborhoods. Five factor-analyzed scales were used to measure community response to freeway noise in terms of (1) subjective reactions and (2) behavioral interruptions due to noise. The social survey allowed for spontaneously mentioned and directly elicited responses. Noise exposure was measured by an Environmental Noise Classifier; one representative noise sample was taken for every residence, and L10, L50, L90, NPL, and TNI were computed. These noise measures correlated highly with each other, except TNI, and none of the measures demonstrated superiority over the others as a predictor of community response. Community response was analyzed as a function of noise level, and all response scales increased with increasing noise levels; for example, freeway noise was reported by 50% as the main cause of dissatisfaction, by 13% as main cause for complaints, by 25% as the reason for wanting to move, and by 43% as the reason for awakening at night. Noise levels correlated 0.99 with mean annoyance ratings for groups of residents within specified noise strata, and 0.31 for ratings based on individual annoyance scores.
Subject Classification: 50.70, 50.50, 50.20, 50.75.
Identification of random auditory waveforms
Authors: Pollack Irwin 
Published: October 2005

Listeners quickly learn to identify, apparently on an absolute basis, the ordering of a pair of sounds, where one sound is a specific random selection which is constant over successive observations, and where the other sound varies over successive observations. The accuracy of identification is not directly related to the uncertainty of the pool of possible waveforms. A wide range of sample durations and spectra characterize the identifiable pools. Increasing the predictability of the sequences does not improve identification accuracy. Listeners also can identify one of two selections from the same pool and can identify departures from a prototype which they have never heard. Since all random selections from the same pool have nearly identical long-term average spectra, it is concluded that the listener must perform a short-term, or running, spectrum analysis upon the signals.
Subject Classification: 65.22, 65.75, 65.68.
Perception of complex sounds: ’’Hidden auditory figures’’
Authors: Pollack Irwin 
Published: October 2005

Hidden auditory figures were generated by ORing the output of a bank of counters, driven by a high-frequency periodic pulse train. The absolute detection, the relative discrimination, and the identification of hidden auditory figures of up to ten prime counts was examined. The crucial factor in detection and discrimination is the context in which the to-be-examined component is embedded. A given count may be nearly perfectly detectable if it is the smallest of the series of prime counts; that same count may be nearly undetectable if it is the largest of the series of prime counts. Within hidden auditory figures, the spread of interference is opposite in direction to most masking situations: High frequencies (represented by small counts) are more effective than low frequencies (represented by large counts). Many of the crucial details are to be found in the spectrum of these signals.
Subject Classification: 65.22, 65.56, 65.75.