摘要:

The dependence of spectral‐shape discriminations upon presentation level was studied using stimuli consisting of a bandpass noise and a less intense pure tone. The level of the noise band was held constant (+10 dB) relative to the level of the tone, and the minimum change in the intensity of the tone was measured across a range of presentation levels. The results demonstrated that, for tonal frequencies located near the upper edge of the noise band, subject’s optimal performance occurred at intermediate presentation levels and became considerably poorer at high levels. This result is in accordance with upward spread of masking and emphasizes that presentation level is an important parameter to consider when measuring discriminations of complex spectral shapes.

ISSN:0001-4966    

DOI:10.1121/1.392778

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

摘要:

The intensity dependence of signal processing in the cat cochlea was studied in responses of single auditory‐nerve fibers for harmonic complexes having various amplitude and phase spectra. Analyses were based on information present in temporal discharge cadences, and they consisted of assessing Fourier spectra of period histograms synchronized to the period of the waveform fundamental. At low intensities, response spectra resembled filtered versions of the stimulus spectrum, with the amounts of filtering being determined by fibers’ tuning curves. At high intensities, response spectra exhibited nonlinear behavior and could differ dramatically from spectra obtained at low intensities. The high‐intensity response typically emphasized one or more aspects of the stimulus spectrum. When the stimulus possessed equal component amplitudes and phases, the features that were emphasized at high intensities were the high‐ and low‐frequency edges of the spectrum, and when the component at fiber CF was changed in phase or amplitude relative to the others, fibers primarily signaled the presence of the phase‐ or amplitude‐shifted component. Many of the intensity‐dependent changes in response spectra are accounted for by considering the effects of the compressive input–output nonlinearity operating at or peripheral to the hair‐cell level on the temporal waveform.

ISSN:0001-4966    

DOI:10.1121/1.392779

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

摘要:

A difference equation simulator for a linear physical system specified in terms of either a differential equation or a rational function ofscan be derived by applying the bilinear transform. It is shown how the method may be extended to enable simulation of nonlinear systems. The same formal procedure can be used with higher‐order (e.g., Runge–Kutta) integrators to give considerably enhanced accuracy for the same step size. Three simple examples are given illustrating the method.

ISSN:0001-4966    

DOI:10.1121/1.392780

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

摘要:

A simple technique is derived for including in the parabolic equation underwater acoustic propagation model the losses due to conversion of compressional waves into shear waves at the water–bottom interface.

ISSN:0001-4966    

DOI:10.1121/1.392729

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.393124

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.392730

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.392731

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.392736

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.392737

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.392740

出版商:Acoustical Society of America    

年代:1985

数据来源: AIP