摘要:

Behaviorally determined thresholds of audition for three species of monkey (squirrel, rhesus, and cynamolgus) are reported. Three different testing procedures were utilized for measuring the threshold: namely, avoidance conditioning in a double‐grill cage and bar‐pressing procedures with reward and avoidance reinforcements. There was good agreement among the audiograms obtained for various species despite the different conditioning procedures used.

ISSN:0001-4966    

DOI:10.1121/1.2143403

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

摘要:

Listeners tracked the trajectories of auditory images produced by a group of three clicks, of which two were temporally fixed in opposite ears and the third ranged freely in time. The fixed clicks were positioned in three time‐ and level‐difference combinations to produce a centered image. The results indicate that the temporally variable click interferes with the fixed‐clicks image when it leads or lags by as much as approximately 25 msec. The leading interference is plausibly explained by monaural forward masking, but the lagging interference is puzzling, partly because it seems inconsistent with results of other experiments in which the two fixed clicks are in one ear and the variable click is in the other. It was also found that the variable click leading by 5 msec or less completely governs lateralization. It was concluded that monaural forward masking obstructs determination of complex binaural interactions.

ISSN:0001-4966    

DOI:10.1121/1.1909292

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

摘要:

The input impedance of conducting piezoelectric plates, excited to thickness vibrations, is calculated and the equivalent circuit is shown. Antiresonance and resonance appear as maximum and minimum the resistance curve. They are just as strongly excited ifω0τ = 1. (ω0 = 2π×resonance frequency, τ =RC, the relaxation time of the circuit far from resonance.) Contrary to the case with nonconducting piezoelectric resonators, higher harmonics are advantageous for determining the electromechanical coupling coefficient.

ISSN:0001-4966    

DOI:10.1121/1.1909294

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

摘要:

The development and evaluation of a new speech‐intelligibility test suitable for routine use by operational personnel in determining the performance level of speech‐communication systems is described. The format used is similar to that described for a rhyme test but makes use of a closed‐response set. An experiment was performed to determine the general reliability of the test materials when administered to U.S. Air Force enlisted personnel under a wide range of signal‐to‐noise ratios. Testing of 18 listeners over a period of 30 days showed that repeated exposure to the materials did not change the levels of average response in any appreciable way. Analysis of the responses to individual phonetic elements shows that the test can be useful for diagnostic study as well as for over‐all evaluation of communication systems. Talker differences that appeared during the experiment and the statistical reliability and sensitivity of the materials are analyzed and discussed.

ISSN:0001-4966    

DOI:10.1121/1.1909295

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

摘要:

Conflicting reports regarding the influence of mental tasks on auditory fatigue have recently appeared in the literature. In the present study, 10 male subjects were exposed to a 4000‐cps fatigue tone at 40 dB SL for 3 min under conditions of mental arithmetic and reverie. Temporary threshold shifts, as indicated by comparing pre‐ and post‐fatigue thresholds, were consistently greater when subjects worked mental arithmetic during exposure to the fatigue tone than when they engaged in reverie.

ISSN:0001-4966    

DOI:10.1121/1.1909296

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

摘要:

A harmonic point source of sound was placed within the potential core of an air jet and the distortion of its sound field by the jet flow was measured. An axial intensity minimum was observed that increases with increasing velocity, frequency, or temperature. The investigation indicates that the cleft in the heart‐shaded directivity pattern of subsonic jet noise can be attributed mainly to refraction.

ISSN:0001-4966    

DOI:10.1121/1.1909297

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

摘要:

A new speech synthesizer is described, Instead of bandpass filters, it uses oscillators whose phase, frequency, and amplitude can be modulated pitch‐synchronously.

ISSN:0001-4966    

DOI:10.1121/1.1909298

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

摘要:

The intensity distribution of light diffracted by progressive ultrasonic waves is used to find the harmonic structure of these waves. A recursion relation has been found that permits the calculation of the harmonic structure from a set of simultaneous linear equations. The coefficients of these equations are obtained from measurement of the diffraction orders.

ISSN:0001-4966    

DOI:10.1121/1.1909299

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1909300

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP

摘要:

The nonlinear interaction of two sound beams propagating in the same direction is studied. Westervelt's theory for the scattering of a difference‐frequency wave is extended to the case of beams with finite width. A stronger directivity in the scattered sound is obtained, in agreement with the experimental results of Bellin and Beyer.

ISSN:0001-4966    

DOI:10.1121/1.1909302

出版商:Acoustical Society of America    

年代:1965

数据来源: AIP