摘要:

In this paper, we describe an extension of our preliminary theory of intensity resolution [Durlach and Braida, J. Acoust. Soc. Am. 46, 372–383 (1969)] to include loudness comparisons among different types of stimuli. The extended theory relates mean loudness matches to discrimination and provides a framework for the interpretation of results on the intrasubject variability of loudness comparisons. The predicted relation between mean loudness matches and discrimination is essentially the same as that proposed by Riesz [J. Acoust. Soc. Am. 5, 211–216 (1933)]. With regard to the variability of loudness comparisons, the extended model is essentially the same as the preliminary model except that a new term is included in the trace‐mode memory variance to account for the dissimilarity of the stimuli being compared. The model is compared to some published data on loudness matching and discrimination and to some new data of our own on the variability of loudness comparisons obtained in a two‐interval, roving‐level, loudness‐discrimination experiment.

ISSN:0001-4966    

DOI:10.1121/1.381641

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

An efficacious operant‐conditioning procedure for psychophysical experiments with cats is described. The system features (a) restraint of the cat and the use of the liquid reinforcement delivery cup to control orientation with respect to the stimuli, (b) a minimum of apparatus between the cat and a free‐field sound source, (c) two response pedals so that separate ’’Yes’’ and ’’No’’ responses are defined, (d) a discrete trial procedure with reaction time (RT) defined as the time from the onset of a trial until the occurrence of a response, and (e) an effective liquid reinforcer and simple delivery system. Operation of the system was demonstrated with the method of constant stimuli. Detectability was directly related, and median RT for correct ’’Yes’’ responses inversely related, to tone sound pressure.

ISSN:0001-4966    

DOI:10.1121/1.381651

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

The intelligibility of frequency‐compressed speech was measured for four normal and eight hearing‐impaired subjects with sensory‐neural high‐frequency loss. Hearing levels were roughly 40 dB. Four conditions of frequency compression, 0%, 20%, 33%, and 55% were obtained using a Varispeech compressor. The test materials were PB‐50 word lists recorded by one male and one female speaker. The effect of frequency compression was to reduce intelligibility in all cases except one, that of the female speaker at 20% frequency compression. For this case, the hearing‐impaired listeners showed a small average improvement. Although the effect was small, it represents one of the few instances when an experimental evaluation of a frequency‐compression system has yielded positive results with the hearing impaired. i

ISSN:0001-4966    

DOI:10.1121/1.381652

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

The present study investigated the serial or parallel processing of phonemes within a syllable. Subjects were required to press a key, on cue, to indicate whether two successive, binaural CVC syllables were the same or different. The cue was a tone which occurred at varying times after the onset of the second CVC and often interrupted its presentation. Subjects’ accuracy as a function of time was compared for discriminations involving the first, second, and third phonemes. The results show that information about the phonemes within a CVC syllable is accruing simultaneously. The importance of these results for models of speech perception is discussed.

ISSN:0001-4966    

DOI:10.1121/1.381653

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

A hydromagnetic field induced by the interaction between acoustic motions and an ambient magnetic field in an electrically conducting medium propagates with the sound radiation, and is transmitted into adjacent sound‐free regions. This sonomagnetic pseudoradiation is analyzed for an arbitrary acoustic source submerged in a semi‐infinite conducting medium in the presence of a constant applied magnetic field such that the Alfvén speed is much less than the sound speed. We begin by formulating the sonomagnetic field equations, from which we derive a formal solution for unbounded media and earlier source‐free results. Then the solution for monopole, dipole, or more general acoustic sources is developed in terms of Sommerfeld‐like integrals. Explicit reduction of the solution integrals is illustrated by presenting approximations for both nearfield and farfield sonomagnetism external to the medium in the case of ambient magnetic field normal to the semispace surface. The farfield exhibits sonomagnetic pseudowaves radiated to considerable distances by high‐power, low‐frequency acoustic sources. Relevance of the calculation to the ocean environment or laboratory conditions is briefly discussed.

ISSN:0001-4966    

DOI:10.1121/1.381654

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

It is shown that the flow of vibration power through a rigid ’’point’’ connection between flexible plate structures may be evaluated by measuring the imaginary part of the cross‐spectral density between the coupling force and the acceleration at the connection point.

ISSN:0001-4966    

DOI:10.1121/1.381655

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

A discrepancy in the recent paper ’’Monostatic reflection of a plane wave from an absorbing sphere’’ [F.H. Vogtetal., J. Acoust. Soc. Am. 57, 558–561 (1975)] is investigated. Calculations are made by means of a modified method for lucite and polyethylene spheres in water. A serious disagreement between Vogtetal. and us is demonstrated in the case where no absorption is included.

ISSN:0001-4966    

DOI:10.1121/1.381629

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

Scattering of a straight‐crest surface wave which propagates at an oblique angle towards the edge of a thin surface layer on an elastic half‐space is considered. It is demonstrated that the range of incidence (0?ϑi<π/2) is divided into four subranges by three ’’critical angles’’ (ϑ1=arcsinKd/KR, ϑ2=arcsinKS/KR, and ϑ3=arcsinKT/KR). The character of the scattered field changes across these angles. The law of refraction and phenomenon of total reflection for elastic surface waves are derived.

ISSN:0001-4966    

DOI:10.1121/1.381656

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

We have demonstrated the feasibility of employing directly acousto‐optic interactions in an optical fiber to produce a sensitive acoustic detector. Our technique utilizes the phase modulation of an optical beam in a submerged optical fiber coil by sound waves propagating in a fluid. Analysis of our results indicates that the sensitivity of this technique compares well with that of the best available hydrophone.

ISSN:0001-4966    

DOI:10.1121/1.381624

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

An optical farfield method is described for studying the temperature dependence of ultrasound induced optical birefringence in liquids. It requires fewer experimental measurements and assumptions than the more commonly used optical nearfield method and permits a more direct evaluation of theoretical parameters describing the effect. Experimental results are given for castor oil to illustrate the general nature of the results which can be obtained. The method can be extended to a wide range of acoustic frequencies and applied to various interaction mechanisms with only slight modification.

ISSN:0001-4966    

DOI:10.1121/1.381625

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP