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Journal of the Acoustical Society of America

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Jun 1973

Volume 53, Issue 6, pp. 1515-1763

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Sound detection and processing by teleost fishes: a critical review

Arthur N. Popper and Richard R. Fay

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1515-1529 (1973); (15 pages) | Cited 3 times

Online Publication Date: 12 Aug 2005

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The purpose of this critical review is to reevaluate the current experimental literature on fish audition based upon evaluation of structural, physiological and behavioral studies. The specific emphasis of the paper will be to (1) review the recent literature on the psychophysiology of hearing in fishes; (2) look at the subject of fish hearing from the standpoint of auditory mechanisms and their relationship to what is known about hearing in terrestrial vertebrates; and (3) emphasize some questions and areas of research which we feel require more investigation. Based on the data reviewed in the paper we have tentatively concluded that the teleost auditory system is well adapted as a temporal analyzer.

Effect of cavity absorption and multiple layers of wallboard on the sound‐transmission loss of steel‐stud partitions

Wayne Loney

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1530-1534 (1973); (5 pages)

Online Publication Date: 12 Aug 2005

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Sound‐transmission‐loss tests in accordance with ASTM E90‐70 were conducted using steel‐stud partitions with a single or double layer of gypsum wallboard on each face of the studs. These test results were used to investigate the effect on the acoustical performance due to number of layers of gypsum wallboard, the installation of cavity absorption of different types and thicknesses, the size of stud, and the thickness of wallboard used. These test results have been summarized in two ways. First, to offer a method of calculating the change in STC due to changes in the components of a partition of known STC ratings. Secondly, a table showing the effect on the TL values due to each of the changes.

Acoustical privacy in the landscaped office

A. C. C. Warnock

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1535-1543 (1973); (9 pages) | Cited 2 times

Online Publication Date: 12 Aug 2005

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Two landscaped offices were used for field studies of the acoustical isolation value of masking noise, absorptive ceilings and partial‐height screens. The occupants of one of the offices were recruited for a subjective study of the relative acceptability of various masking noises. The study showed that this group consistently preferred less noise — a conclusion that contradicts some previous experience. Interviews indicated that the acceptability of masking noise is closely linked to the occupants' activities and the resulting need for privacy. Propagation measurements were made under a flat lay‐in ceiling configuration to determine the effectiveness of screens, ceiling materials and ceiling baffles. The ceiling baffles were not found to be a practical means of ensuring a low ceiling reflection coefficient. The results of the measurements are analyzed in terms of changes in articulation index. Consideration of the area disturbed by a hypothetical speaker emphasizes the importance of small relative changes in articulation index caused by small changes in physical parameters.

Perstimulatory loudness adaptation

David A. Bray, Donald D. Dirks, and Donald E. Morgan

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1544-1548 (1973); (5 pages) | Cited 1 time

Online Publication Date: 12 Aug 2005

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An experiment is described in which perstimulatory loudness adaptation was measured under heterophonic conditions using simultaneous dichotic loudness balance procedures on normal listeners. The adapting signals were 500 and 3000 Hz presented at 70 dB SPL for 12 min, the last 5 min of which involved perstimulatory loudness balances. A tracking technique and the method of constant stimuli were employed. The results indicated that continuous stimulation did not significantly decrease the loudness of the adapting signal. Thus, under test conditions that reduce or eliminate binaural interaction, suprathreshold loudness adaptation is essentially absent for pure‐tone signals of 500 and 3000 Hz at 70 dB SPL.

The interaural time jnd as a simultaneous function of interaural time and interaural amplitude

R. Domnitz

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1549-1552 (1973); (4 pages) | Cited 10 times

Online Publication Date: 12 Aug 2005

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The interaural time jnd was measured as a simultaneous function of interaural time and interaural amplitude for 500‐Hz tone bursts. It was found that the jnd was smaller when interaural amplitude and interaural time were arranged to produce subjective reinforcement rather than subjective cancellation.

Direct comparison of lateralization and the MLD for monaural signals in gated noise

E. R. Hafter, S. C. Carrier, and F. K. Stephan

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1553-1559 (1973); (7 pages) | Cited 1 time

Online Publication Date: 12 Aug 2005

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The lateralization model of Masking‐Level Differences (MLDs) asserts that detection in those binaural conditions that produce an MLD is directly related to the perception of lateral space. The model was tested here by obtaining subjective reports of the lateral place of dichotic and diotic signals in noise which were in turn used by an “ideal observer” to determine the discriminability of the two classes of stimuli. The results support the model, showing that an observer using no information other than the lateralization judgments could detect NOSM in the dichotic condition as well as a subject who hear the acoustic stimuli.

Suprathreshold loudness adaptation

Donald E. Morgan and Donald D. Dirks

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1560-1564 (1973); (5 pages)

Online Publication Date: 12 Aug 2005

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Experiments were performed to measure suprathreshold loudness adaptation at 500 Hz using a heterophonic listening condition in order to reduce binaural interaction. The adapting stimulus was presented at 70 dB SPL for 7 min. A long (3000 msec) and a short (300 msec) comparison stimulus were chosen to delineate the possible influence of the duration of the comparison stimulus itself on the magnitude of the loudness change measured. No loudness adaptation was observed during these experimental conditions. We interpret these results as corroborating similar findings in another laboratory indicating essentially no loudness change under perstimulatory test conditions in which binaural interaction is reduced. During the initial experiment an apparent “enhancement” of loudness was observed during the adapting period when a train of short pulses (300 msec each) was used as the comparison stimulus. In a second experiment, results suggested that, in fact, there is a loudness disparity between a pulse train and a continuous signal. For conditions where the loudness of a single short pulse is compared to a continuous signal, however, no loudness disparity was observed.

The effects of relative phase and the number of components on residue pitch

R. D. Patterson

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1565-1572 (1973); (8 pages) | Cited 17 times

Online Publication Date: 12 Aug 2005

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The pitch of the residue produced by 6‐ and 12‐component waves whose components were either in cosine or random phase was measured as a function of the frequency region of the components. The components were all of equal amplitude and the frequency spacing between them was 200 Hz. Waves with the same lowest component were found to produce the same pitch: neither the number of components nor the relative phase of the components was important in determining the pitch of the residue. If every component in a wave was a multiple of 200 Hz, the wave produced a 200 Hz pitch; if such a set of components was shifted in frequency by a small amount, there was a corresponding linear shift in the pitch of the residue. When the lowest component in the wave was below about 900 Hz, the slope values associated with the lines relating the pitch shift to the frequency shift varied little from their average value of 0.21. As the lowest component increased from 900 to 2580 Hz the slope values decreased to about 0.08. These findings are in good agreement with the current model of pitch perception based on interpeak durations.

Some determinants of localization‐adaptation effects for successive auditory stimuli

Willard R. Thurlow and Charles E. Jack

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1573-1577 (1973); (5 pages) | Cited 5 times

Online Publication Date: 12 Aug 2005

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Evidence is presented which shows that localization aftereffects can be produced not only by an adapting stimulus which has only an intensity differential at the two ears, but also by one which has only a time‐delay differential at the two ears. In general, the displacement of the test stimulus is away from the perceived location of the adapting stimulus. However, exceptions to this rule have been found. It is concluded that the mechanism of these localization aftereffects is not in some final central location corresponding to perceptual space.

Introduction to electrets

H. J. Wintle

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1578-1588 (1973); (11 pages) | Cited 2 times

Online Publication Date: 12 Aug 2005

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A short review will be given of the types of electret in terms of their electrostatic configuration: dipolar, internal space charge (heteroplar), injected space charge (homopolar), and deposited charge (monopolar). The methods used to make thermo‐, photo‐, electro‐, and surface electrets will be described. The internal fields, short‐circuiting effect, stability, limitation due to air breakdown, charge measurement, charge storage, and trapping levels will be discussed.

Electret transducers: a review

G. M. Sessler and J. E. West

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1589-1600 (1973); (12 pages) | Cited 14 times

Online Publication Date: 12 Aug 2005

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A review of the history, design, performance, and application of electret transducers is presented. Particular emphasis is placed on foil‐electret transducers incorporating a thin‐film electret made of Teflon or related materials. Such transducers have excellent frequency response, low distortion, small vibration sensitivity, and have been used over a frequency range extending from 10−3 to 2 × 108 Hz. They can be made in a variety of shapes over a large range of sizes and are generally not affected by adverse environmental conditions. More than 10 million electret transducers are being manufactured annually as microphones with various directivity patterns for use in amateur and studio applications, tape recorders, sound‐measuring instruments, telephone‐operators' headsets, hearing aids, and acoustic‐graphic tablets, and as transducers in earphones and phonograph cartridges. Electret transducers are also used for experimental and research applications in such widely different fields as gas analysis, opto‐acoustic spectroscopy, aeronautics, atmospheric studies, telephony, ultrasonics, acoustic holography, data transmission, and leak detection in space stations.

Electrets in miniature microphones

Freeman W. Fraim, Preston V. Murphy, and Robert J. Ferran

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1601-1608 (1973); (8 pages) | Cited 2 times

Online Publication Date: 12 Aug 2005

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The electret capacitive microphone element is ideally suited for miniature applications. However, because these miniature elements represent very high impedances at audio frequencies, a complete microphone will almost always incorporate a high input impedance preamplifier, which is a source of noise in the microphone. Proper design of both the preamplifier and electret element is required in order to avoid poor signal‐to‐noise ratio. The electret element and accompanying preamplifier are electrically modeled to indicate the important parameters for minimizing the noise. This model is then coupled with the performance equations for two simple electret element geometries to indicate the effects of a noisy preamplifier on the optimum element design. The results indicate that the best signal‐to‐noise level is not obtained at the design point which yields the maximum acoustic sensitivity, but at conditions which maximize the electret element capacitance. The characteristics of two typical wide‐band electret microphones are given to indicate the type of performance actually possible from very small microphones.

Noise‐cancelling electret microphone for lightweight head telephone sets

C. W. Reedyk

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1609-1615 (1973); (7 pages) | Cited 1 time

Online Publication Date: 12 Aug 2005

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The design of a small (0.8×0.5×0.2 in.) and light (1 g) noise‐cancelling microphone based on the electret transducer is described. The microphone, mounted at the end of a boom, is used for a new operator's headset. The basic electret transducer is used as a first‐order gradient microphone whose directional characteristic is adjusted so that, for a given bandwidth and background noise spectrum (speech from nearby operators), the noise‐cancelling property is optimized. Pratical results indicating a minimum of 8 dB noise rejection are presented.

Optimization of a ridge backplate for electret microphones

H. S. Madsen

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1616-1619 (1973); (4 pages)

Online Publication Date: 12 Aug 2005

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The desired properties for most microphones are high sensitivity, flat frequency response, insensitivity of response to vibration and temperature fluctuations, and long life. The life of an electret is particularly important since the self‐polarization has a natural decay. It is possible, however, to design an electret microphone that has little variation in sensitivity even though the charge density of the trapped charges diminishes to 1/4 of its original value. This is possible by controlling every contributing parameter. The parameter that is hardest to control is the tension of the polymer diaphragm and the problem has been resolved by choosing a rectangular backplate with a diaphragm tensioned across parallel ridges. Stray capacitance and electrical load are among the parameters that affect the stability of the microphone, especially when the microphone becomes small as for a lightweight operator's headset. The results of computations and experiments are given.

Electronic simulation of violin resonances

M. V. Mathews and J. Kohut

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1620-1626 (1973); (7 pages) | Cited 4 times

Online Publication Date: 12 Aug 2005

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A study of the resonances of the violin is described. Magnetic pickups attached to the bridge of a violin (sans body) responded to the lateral motion of the strings to produce a signal used to excite a set of electrical resonances. The parameters, such as center frequency, bandwidth, and attenuation of the resonances were adjustable and by means of these variables a variety of tones were produced and presented to experienced subjects from the music world. Subjective evaluation of the various tones indicates that the preferred violin tone is produced when the resonance frequencies are irregularly spaced with respect to the harmonics of the string vibration and the bandwidths have values which achieve a 12‐dB peak‐to‐valley differential in the resonance response curve. A theory of enhancement of tone quality by resonant filters is presented and the construction of an electronic violin is discussed.

Background noise for acoustic emission in a boiling water and a pressurized water nuclear‐power reactor

S. P. Ying, J. E. Knight, and C. C. Scott

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1627-1631 (1973); (5 pages)

Online Publication Date: 12 Aug 2005

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The acoustic noise spectra from 0 to 700 kHz of a boiling water reactor (BWR) have been normalized and compared with the available noise data of a pressurized water reactor (PWR). At frequencies near 500 kHz, which is the interesting frequency range for acoustic emission technology, the hydraulic turbulent and cavitation noises of the PWR were about 0 dB for the selected normalization and the noises of the BWR varied from 0 to 15 dB for the various locations that were monitored. Since the intensity levels of acoustic emission signals are on the order of 0 to 20 dB, the PWR background noise should not completely mask them; however, the BWR noise would obliterate some weak acoustic signals in some locations but allow them to be observed in other locations.

A new inverse‐filtering technique for deriving the glottal air flow waveform during voicing

Martin Rothenberg

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1632-1645 (1973); (14 pages) | Cited 12 times

Online Publication Date: 12 Aug 2005

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A method is described for deriving the volume velocity waveform at the glottis during voiced speech by inverse‐filtering the volume velocity waveform at the mouth. Unlike the previously used technique of inverse‐filtering radiated acoustic pressure, this method provides a signal that is accurate down to zero frequency, not susceptible to low‐frequency noise, and easily calibrated in amplitude by a constant air flow. The primary limitation is the need for a transducer that will measure volume velocity at the mouth with adequate fidelity. In this work, volume velocity was recorded from a specially designed circumferentially vented wire screen pneumotachograph mask which provided a time resolution of 1/2 msec, without serious speech distortion. Inverse‐filtered volume velocity was recorded with two adult male subjects for voicing in the modal register. Typical results are shown which indicate the way in which the glottal waveform varied with changes of fundamental frequency, subglottal pressure, and a dimension of voice quality related to the degree of compression of the vocal folds. Also considered are the effects of glottal‐supraglottal acoustic interaction, and the effect on the glottal waveform of air displaced by the movements of the vocal folds.

Signal processing to improve speech intelligibility in perceptive deafness

Edgar Villchur

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1646-1657 (1973); (12 pages) | Cited 18 times

Online Publication Date: 12 Aug 2005

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A deaf person with recruitment perceives sound as though listening through a volume expander followed by an attenuator, the expansion ratio and attenuation being typically frequency dependent. (Other perceptive aberrations may also be present, of course.) The subject is often prevented from using enough hearing‐aid gain to bring weak consonants into the useful dynamic range of his hearing, because this amount of gain would make lower‐frequency, high‐amplitude vowels intolerably loud. Such subjects commonly find amplified speech to have poor intelligibility. In a preliminary experiment it is established that recruitment in normal subjects, induced by masking or simulated by expansion of the signal, reduces the intelligibility of amplified speech severely, and that this intelligibility can be largely restored by signal processing. The implication is that recruitment in deaf subjects is a sufficient cause for loss of intelligibility, whether or not there are other causes. In the present experiments, speech is processed by a two‐channel amplitude compressor whose frequency‐dependent compression ratio is adjusted to compensate the recruitment of the individual subject, and the compressed speech is subjected to frequency‐selective amplification similarly adapted to the subject. The aim is to amplify each acoustical element of speech, at each frequency‐amplitude coordinate of the speech band, to a relative loudness for the deaf subject corresponding to the relative loudness of that speech element perceived by normals. This processing improved speech recognition, both in quiet and in the presence of competing speech introduced before processing, for six perceptively deaf subjects. Subjects showed an improvement in either initial‐ or terminal‐consonant recognition of at least 22% and as much as 160% at optimum levels in quiet, and from 10% to 229% with speech interference 10 dB below the pre‐processed signal.

Energy of the acoustically excited surface wave on a flat semi‐infinite elastic medium

Robert E. Bunney and Ralph R. Goodman

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1658-1662 (1973); (5 pages) | Cited 2 times

Online Publication Date: 12 Aug 2005

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An analysis is made of the distribution of intensity of the evanescent waves in a semi‐infinite elastic medium when a plane acoustic wave in a contiguous fluid medium is incident upon it. It is found that the maximum intensity and total energy in the evanescent wave occurs at the angle of incidence corresponding to the Rayleigh angle [θR  =  sin−1(C 0/CR), where CR is the Rayleigh wave speed and C0 is the sound speed in the fluid medium]. This result gives insight both mathematically and physically as to what should be expected for surfaces with curvature as well as for plates.

Electrostatic ultrasonic transducers and their utilization with foil electrets

D. Legros and J. Lewiner

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1663-1672 (1973); (10 pages) | Cited 3 times

Online Publication Date: 12 Aug 2005

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Electrostatic ultrasonic transducers are very attractive when considered from the point of view of simplicity. They are constituted by a condenser, the ultrasonic wave being directly excited on the electrodes. These transducers are currently used at low frequencies (microphones) and sometimes at higher frequencies (up to a few megahertz). At higher frequencies the bias voltage applied across the condenser has to be quite large and electrification of the central dielectric layer can appear. This paper describes such effects and presents the experimental conditions allowing the transducer to operate. The electrification of the dielectric layer is studied and the problems related to the conservation of the deposited charges are considered for Mylar and polypropylene foils of about 10‐μ thickness. In the present work the ultrasonic waves generated or received by these transducers have frequencies ranging from 10 to 200 MHz.

Resonance generation of ultrasonic second harmonic in elastic solids

R. D. Peters

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1673-1676 (1973); (4 pages)

Online Publication Date: 12 Aug 2005

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Second harmonic and fundamental standing‐wave amplitudes have been measured to see if nonlinearity parameters (combinations of third‐order elastic constants) can be determined from measurements made on samples driven at resonance. A model for the resonance is formulated by considering the process of overlap for a sample‐applied pulse whose length is extended to many overlap orders. Attenuation is included in the model, and the nonlinearity parameters obtained from the application of the model to experimental data are compared with values from other experiments.

Specularly scattered sound and the probability density function of a rough surface

Clarence S. Clay, Herman Medwin, and Wayne M. Wright

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1677-1682 (1973); (6 pages)

Online Publication Date: 12 Aug 2005

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The coherent component of specularly scattered underwater sound is sensitive to the probability density function (PDF) of displacements of the rough surface. For the specular reflection of diverging waves, the coherent component and the PDF are shown to be related by the Fourier transformation. Laboratory measurements of sound scattered at a partially shadowed nearly Gaussian model sea surface show the coherent component is much larger than would be expected for a Gaussian PDF. Fourier transformations of the measured PDF, on inclusion of a shadowing correction, gave the coherent component. Fourier transformation of the coherent component yields a surface PDF similar to the measured PDF with shadowing correction.

The wave equation in a medium with a time‐dependent boundary

Leonard Fortuin

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1683-1685 (1973); (3 pages) | Cited 1 time

Online Publication Date: 12 Aug 2005

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It is shown that the Helmholtz equation is not exactly correct for a medium with a time‐dependent boundary. The equation can be used with very good approximation when the time‐derivative of the surface elevation is much smaller than the speed of the waves through the medium. For underwater sound waves, reflected and scattered by an ocean surface that can be described by the Pierson‐Moskowitz spectrum, this means that the wind speed has to be much less than the sound speed.

Short‐range transmission loss and the evidence for bottom‐refracted energy

J. S. Hanna

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1686-1690 (1973); (5 pages)

Online Publication Date: 12 Aug 2005

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Transmission loss over the range of the direct arrival is examined for a receiver lying on a deep, sedimentary ocean bottom and is found to exhibit interference structure not explained by water‐borne paths alone. It is suggested that this structure can be understood in terms of energy refracted through the sediments back to the receiver. The velocity structure in the sediments required to account for the interference is quite consistent with the velocity structure inferred from seismic profiling the vicinity of the receivers.

CW beacon system for hydrophone motion determination

R. P. Porter, R. C. Spindel, and R. J. Jaffee

J. Acoust. Soc. Am. Volume 53, Issue 6, pp. 1691-1699 (1973); (9 pages)

Online Publication Date: 12 Aug 2005

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A system consisting of three bottom‐moored 12 000‐Hz CW beacons, each separated in frequency by 40 Hz, and separated in space by about 8 km, has been used to track the motion of ship‐suspended, ship‐mounted, sonobuoy‐deployed, and bottom‐moored hydrophones to an accuracy of 4 cm. The system uses Doppler tracking of the beacon signals to provide real‐time estimation of hydrophone velocity and displacement. Factors that might compromise system performance, such as surface, bottom or forward volume scattering, or multipath effects, were found to be negligible. Random phase fluctuations in beacon signals due to these phenomena are small compared with those due to hydrophone motion. Two tests of the system, near Eleuthera Island and near Bermuda, were made in September–October 1972. [This work was performed under U.S. Office of Naval Research Contract No. N00014‐72‐C‐0205.].
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