摘要:

The known criteria of room acoustics are not sufficient to characterize the quality of concert halls. To obtain more specific information on the acoustic qualities of concert halls, the author went on tour with the Cleveland Orchestra, making measurements in 15 concert halls. These measurements revealed that the dynamic range of performed music and also the tempo are different in the several halls. The dynamic range depends on the noise level of the room and the state of sound diffusion. The tempo of music is at a maximum in concert halls which have optimum reverberation time and diffusion.

ISSN:0001-4966    

DOI:10.1121/1.1909024

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

This experiment principally attempted to map the movements of lateralized auditory images associated with 1‐pps unfiltered clicks heard at two intensity levels and over a wide range of interaural time and intensity differences. With sensation level at 16 db in both ears, lateralization effects were heard for interaural time differences as large as ±15 msec. With 16 db SL in one ear, the minimum level in the other ear producing effects was −6 db, the effect usually being a “bulge” of the image in the audible ear occurring within ±2 msec interaural time difference. Approximately the same time‐difference limits were found, respectively, for 36 db in both ears and 36 db in one ear paired with the minimally effectual −2 db in the other ear. The time‐difference limits within which fusion was “complete” (only one image heard) ranged from 3–7 msec, louder ear leading, to 3 msec, louder ear lagging. It is suggested that the results set a bound on the contribution of direct binaural correlation to the precedence‐effect phenomenon.

ISSN:0001-4966    

DOI:10.1121/1.1909026

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

Using the method of magnitude estimation, the experiments reported investigated the effect of the frequency of the standard upon the pitch functions for piano tones and randomly chosen pure tones. The pitch functions obtained are found to agree in an important respect with each other and with the function previously reported for pure tones chosen to correspond to notes on the musical scale. When the frequency of the standard was the lowest tone presented, the magnitude estimations yielded a function similar to the revised mel scale, and when the standard was a frequency nearer the middle of the series, the magnitude estimations yielded a steeper function closer to the original mel scale. Data are also presented showing that the numerical value of the standard can affect the magnitude estimation function. These results indicate that response biases relating to the frequency and numerical value of the standard may be expected to influence the pitch function determined by magnitude estimations. The nature and effect of these biases are discussed. It is concluded that care is required in viewing magnitude estimation judgments as reflecting a simple correspondence between frequency and the sensation of pitch.

ISSN:0001-4966    

DOI:10.1121/1.1909028

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

The eighth nerve action potential in the cat was recorded from the round window and from the eighth nerve. The conduction velocity, measured directly and computed from the fiber diameter, was found to be approximately 25 m/sec. Comparison of the onset of the action potential at the round window and its appearance in the eighth nerve showed a delay of 0.3 msec, based upon the theoretical time of transmission according to the conduction velocity. As the stimulus intensity was increased, a decrease in the latency of the action potential of the eighth nerve was noted.

ISSN:0001-4966    

DOI:10.1121/1.1909030

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

The cochlear ac potentials in response to a stimulating tone of rapidly increasing intensity undergo a rapid reduction in amplitude after reaching a certain maximum. The record seen on the cathode ray screen is indistinguishable from that reported for middle ear muscle action, yet the response described here occurs in the absence of muscles or of the entire middle ear. This effect is described as a “clamp,” but it is found to be the result of overloading in the inner ear. Within the limits of these experiments it is shown that the rate of rise of a tone makes no difference in the form of the cochlear ac response. This finding, if carried to extremes, would suggest that the inner ear behaves the same in the presence of impact noise as it does in the presence of steady‐state or slowly rising tones.

ISSN:0001-4966    

DOI:10.1121/1.1908976

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

A different technique of analysis is applied to the experiment suggested by Harvey Fletcher for measuring the width of the critical band. This experiment determines the ability of noise bands of different widths to mask a pure tone centered in the band. The analysis considers two filters in series, one outside and one inside the observer. The width of the second filter (the critical band) can be estimated from measurements of the reduction in the noise power at the detector which is effected by the pair of filters. The width of the critical band is estimated under four different assumptions about the shape of the band. The results provide a context for discussing the reasons that may underlie the widely varying estimates of the critical bandwidth which have been obtained in previous studies.

ISSN:0001-4966    

DOI:10.1121/1.1908978

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

Appreciable experimental data exist for the amplitude of basilar membrane displacement as a function of sound frequency. Data on the phase of displacement vs frequency are relatively meager. At low frequencies the latter do not relate well to the phase predicted by recent mathematical models for membrane displacement. To examine the difference, we programmed a digital computer to calculate: (1) minimum phase functions corresponding to the experimental amplitude vs frequency responses; (2) inverse Fourier transforms of the experimental amplitude and phase data; and (3) inverse transforms of the experimental amplitude and calculated minimum phase data. The results were: (1) At low frequencies the calculated phase differs from the experimental phase by about12πradians or more, with the membrane displacement leading that of the stapes. Constant delay (i.e., linear phase) does not account for the difference; (2) inverse transforms of the experimental data yield nonrealizable impulse responses, i.e., responses which are nonzero for negative times; and (3) inverse transforms of the experimental amplitude and calculated phase yield proper impulse responses. At low frequencies, therefore, the experimental amplitude and phase data do not seem completely compatible. For several reasons, the phase data seem more likely to include a small imprecision than do the amplitude data.

ISSN:0001-4966    

DOI:10.1121/1.1908980

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

The empirical rule that interrupted noise having an on‐fractionRproducesRtimes the TTS that the same noise would produce if on continuously (the on‐fraction rule) was tested forR≈0.5 and for various duty cycles from 1 min to 16 min. The TTS from the 1‐min and 2‐min duty cycles agreed with the value predicted by the rule, but the 4‐min, 8‐min, and 16‐min duty cycles gave respectively 1.07, 1.21, and 1.29 times theR‐based values. This result indicates that the on‐fraction rule breaks down when on‐off times exceed about 1 min, but that the rule may be extended for periodic or nearly periodic noises by incorporating correction factor based on the length of the period.

ISSN:0001-4966    

DOI:10.1121/1.1908982

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1908984

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

The hypothesis is advanced that a time‐invariant pattern of frequency response can be discriminated in the presence of a variable pattern of frequency‐response irregularity only when the listening interval is of sufficient duration to allow the variable part of the total response pattern to be averaged out. Qualitative evidence seems to support the hypothesis, but quantitative evaluation of the needed integration times is still wanting. If the effect is real, however, it may have an important bearing on the interpretation of the conventionalA ‐ Btests used for the assessment of sound reproducing systems.

ISSN:0001-4966    

DOI:10.1121/1.1908986

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP