摘要:

This study demonstrates the application of a multidimensional scaling technique, known as INDSCAL, to determine the perceptual attributes of a group of non‐normal voices. In this study, equal‐appearing interval scale was used to obtain judgments of similarity for 20 speakers sustaining a vowel. For each speaker, six physical and three psychophysical measures were also obtained and used to interpret the INDSCAL solution. A five‐dimensional solution was found to be the most appropriate solution for explaining the variance. The findings of the INDSCAL analysis suggest that there exist distinct perceptual features of the abnormal voice which have physical and psychophysical correlates. The strengths of the underlying dimensions of the voices appear to indicate that multidimensional scaling will be a valuable tool in the diagnosis of voice abnormalities.

ISSN:0001-4966    

DOI:10.1121/1.381439

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

A method is presented for the estimation of the abundances of scatterers from their backscattering spectra. It uses constrained steepest descent and gives optimal estimates in the least‐squares sense. The population distributions of fish with gas‐filled swim bladders, calculated from a set of backscattering measurements taken in the ocean near Oregon, are generally consistent with midwater‐trawl samples in the same area.

ISSN:0001-4966    

DOI:10.1121/1.381440

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

There has been a recent expression of concern that the metal shells of most audiometric earphones could consitute a safety hazard because they can conduct electricity and are often used near electrical‐power supplies. In response to this potential safety hazard, Telephonics has constructed new TDH‐49, and TDH‐50 earphones with nonconducting outer shells. Real‐ear threshold comparisons were used to determine if the samples of plastic‐cased earphones could be substituted directly for the standard, metal‐cased earphones. The ten, trained‐listener subjects showed normal audiometric thresholds with good reliability. The real‐ear performance of the plastic‐cased earphones did not differ significantly from the of the metal‐cased earphones and it was concluded that these earphones could be used interchangeably in audiometric testing.

ISSN:0001-4966    

DOI:10.1121/1.381441

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

In obtaining normal‐mode solutions of the wave equation in a horizontally stratified ocean, a choice may be made between two different branch cuts in the complex plane. The solution based on the Ewing–Jardetsky–Press cut consists of two terms, (1) the sum of a finite number of ’’proper’’ modes and (2) a branch line‐integral contribution. The solution based on the Pekeris cut consists of three terms, (1) the ’’proper’’ mode sum, (2) the sum of an infinite number of ’’improper’’ modes, and (3) a branch line‐integral contribution. It is found in two examples that a solution based on the Pekeris cut leads to the same results as Stickler’s solution based on the Ewing–Jardetsky–Press cut.

ISSN:0001-4966    

DOI:10.1121/1.381442

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

Robert Kennedy’s calculations on applications of optimal beamforming to turbulence‐noise cancellation are extended to the case of an arbitrary number of equispaced collinear point sensors. A limiting expression is obtained for a factor that provides the amount of reduction of the flow noise component to the output. Additionally, the arguments corresponding to the first two minima of this factor are also computed.

ISSN:0001-4966    

DOI:10.1121/1.381443

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

The equation for the correlation of a pair of arbitrarily positioned sensors in a noise field produced by a uniform distribution of independent dipole noise sources on a distant surface results in a pair of integrals. It is shown here that one of these integrals can be evaluated analytically to obtain a closed‐form result.

ISSN:0001-4966    

DOI:10.1121/1.381444

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

摘要:

This paper purports to compare the effect of temperature and humidity on three different types of microphones; air‐cpndenser, electret‐condenser, on three different types of microphones; air‐condenser, electret‐condenser, and ceramic. One type, the air condenser, is ’’back vented through a d dehumidifier’’ and is thus not really exposed to humidity. It is not surprising to find that it is unaffected by humidity when protected in this way. Tables that are alleged to demonstrate long‐term stability show changes in sensitivity that are probably due to residual moisture in the microphones.

ISSN:0001-4966    

DOI:10.1121/1.381445

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.381475

出版商:Acoustical Society of America    

年代:1977

数据来源: AIP