摘要:

It is difficult to explain the extraordinary capacity of the ear in discriminating pitch without assuming the existence of laterally inhibitory neural nets fed by cochlear potentials. On such an assumption, we have sought to show edge effects in direct auditory masking analogous to Mach bands found in vision. Noise bands having theoretically infinite attenuation rates outside the passband were generated by computer from 56 sinusoids spaced randomly by frequency. Monaural pure‐tone‐masked audiograms were obtained for each of four subjects for each of two such noise bands (480–580 Hz and 960–1160 Hz) at sensation levels of 20, 30, 40, 50, and 60 dB. Edge effects, as measured by contours of threshold shift, were revealed for all subjects, at every loudness, and were similar for both noise bands. Sharpening was greater at the low frequency end of a band and grew nonlinearly with loudness, as did upward spread of masking. Sharpening was greater for an interrupted than for a continuous masked tone and may be maximal for relatively low interruption rates. The data are consistent with the existence of laterally inhibiting neural nets and are discussed in relation to their neural basis and to other phenomena such as the pitch of noise bands and the regions of increased sensitivity often found in abrupt hearing loss.

ISSN:0001-4966    

DOI:10.1121/1.1911575

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

The theory of differential electrode technique is briefly reviewed, especially as it pertains to the recording of remote CM. Median isopotential curves for the first‐ and third‐turn electrode placements are given for 18 guinea pigs. The differences and similarities between differential and single intracochlear as well as round‐window electrodes are discussed. Special attention is paid to the CM that is recordable from the third turn at high frequencies with differential electrodes. On the basis of dc polarization experiments, it is concluded that this high‐frequency CM is not a local response. Some performance criteria for the evaluation of the adequacy of differential electrodes are developed.

ISSN:0001-4966    

DOI:10.1121/1.1911576

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Amplitude‐discrimination performance is found to be independent of the duration of the signals to be discriminated for durations ranging from 20 to 200 msec provided that the ratio of signal energy to noise‐power density is kept constant. If the ratio of signal energy to noise‐power density is manipulated by altering either the noise‐power density or the signal duration, then discrimination performance is also independent of that ratio once it exceeds 20 dB. The implication of these findings is discussed.

ISSN:0001-4966    

DOI:10.1121/1.1911485

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Sixteen brief sounds (music, vehicle sounds, and artificial sounds) were judged on each of 15 bipolar scales by 20 subjects. Without instructions, subjects use the descriptors “loud” and “noisy” as synonomous. On the other hand, subjects do not equate either loudness or noisiness with acceptability, although there appears to be a moderate relationship when only vehicle or aircraft sounds are rated by subjects. The implications of these findings for instructions in psychoacoustic research are discussed.

ISSN:0001-4966    

DOI:10.1121/1.1911487

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Perstimulatory suprathreshold adaptation was measured in 38 normal adult persons between 250 and 6000 Hz at 20, 40, 60, and 80 dB SL. In the experimental ear, the continuous stimulus had a constant intensity. In the control ear, the adjustable balancing stimulus had a duration of 200 msec with a silent interval of similar length. Adaptation increased at all frequencies as a function of SL up to 60 dB, but testing at 80 dB brought no further increase. At low tones, adaptation was smaller than at high frequencies. There were large individual differences; 5% showed no adaptation at all, 45% a very rapid growth, and 50% a slower adaptation reaching a maximum in212–3 min. Average adaptation was 30 dB at the high frequencies. In children, the same test generally revealed no adaptation at all; in old age, adaptation was comparable to the normal adult group.

ISSN:0001-4966    

DOI:10.1121/1.1911489

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Jitter‐detection thresholds were determined over a wide range of pulse levels and in the presence of band‐limited masking noise. Pulse level modifies jitter thresholds of high pulse frequencies substantially more than that of low and intermediate pulse frequencies. This result is apparently at variance to that predicted by a simple temporal coding underlying auditory jitter. Noise masking is substantially more effective upon relatively low‐frequency pulse trains (average interpulse intervals between 2 and 15 msec) than upon higher‐frequency pulse trains. Noise masking by low or high noise frequencies is substantially less effective than intermediate noise frequencies, in the vicinity of 1 kHz. This frequency region has also been implicated by other investigators as critical for pulse‐frequency discrimination.

ISSN:0001-4966    

DOI:10.1121/1.1911491

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Spike discharges from single fibers in the auditory nerve of anesthetized cats were recorded with micro‐electrodes. Rates of discharge were measured as functions of the frequencies and levels of either single tone bursts or of the sum of two simultaneous tone bursts. From these data, a mathematical expression relating rate of discharge to parameters of a two‐tone stimulus is derived. The rate of response is written as the sum of a “spontaneous” part and a driven part. The driven part of the response to two tones is a weighted sum of the driven parts of the responses to the individual tones presented alone. The weighting factors to a first approximation depend only on the ratio of the levels of the two tones and on their frequencies. The relationship of this stimulus response formulation to existing data and to auditory system models is discussed.

ISSN:0001-4966    

DOI:10.1121/1.1911493

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

A constant‐geometry amplitude‐detection method for establishing the acoustic velocity of gases confined in tube, which was suggested earlier, has been employed successfully. This method is also compared with two other suggested amplitude‐detection schemes and with the phase‐detection scheme of El‐Hakeem.

ISSN:0001-4966    

DOI:10.1121/1.1911495

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

Three sound‐transmission anomalies in the atmosphere are discussed, and explanations are suggested.

ISSN:0001-4966    

DOI:10.1121/1.1911497

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP

摘要:

The complete bistatic scattering pattern of a rough surface with known statistical properties has been obtained for angles of incidence 10° apart from the vertical down to 30° from grazing using 1‐MHz acoustic waves in water. Bistatic patterns corresponding to other incident angles within this range can easily be interpolated, thus giving rise to what is believed to be the first such complete set of scattering patterns. The surface was formed from a sheet of mild steel, after which the roughness was sampled along profiles and the surface statistics computed. The roughness was such that the standard deviation was approximately12of the incident wavelength and the correlation distance was about 18 wavelengths. The availability of these complete scattering patterns is important to the understanding of the basic scattering process. They allow, for the first time, comparison of the various scattering theories to experimental measurements for other than the plane of incidence. Also pointed out is the transition of the shape of the patterns as the incident angle is changed.

ISSN:0001-4966    

DOI:10.1121/1.1911499

出版商:Acoustical Society of America    

年代:1969

数据来源: AIP