摘要:

In this note, the Huggins creation of pitch stimulus is regarded as a binaural masking stimulus and the equalization and cancellation model of binaural masking level differences is applied to the creation of pitch phenomenon.

ISSN:0001-4966    

DOI:10.1121/1.1918251

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

The authors describe the methods used and results obtained in a series of experiments designed to examine the effects of unilateral auditory masking upon the apparent position of a sound in space. Listeners were asked to locate various pure‐tone and complex‐sound signals delivered by a concealed loudspeaker while pure tone or complex masking stimuli were delivered to one ear by means of a single headphone. The results of these experiments indicate that masking can have a strong and consistent effect in pulling the apparent source of the free‐field signal toward the masked ear. The authors interpret this as evidence that binaural interaction is taking place and stress that most other methods of examining the phenomenon would fail to detect interaction between the types of stimuli used. The experimental data also indicate that intensity and frequency relations between signal and mask play a major role in determining the extent to which a masking stimulus will pull the apparent source of sound toward the masked ear; the effect is striking when the frequency spectrum of the mask covers that of the free‐field signal; the effect may still be evident, however, when signal and mask have no frequency components in common. The wide range of frequency relations between interacting signals and masks is consistent with the findings of neurophysiological and neuroanatomical studies of the auditory nervous system.

ISSN:0001-4966    

DOI:10.1121/1.1918252

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

“Backward masking” is the term used to denote the situation in which one auditory stimulus is masked by another auditory stimulus which follows it in time while in “forward masking” the temporal positions of masking and masked signals are reversed. In this study, backward and forward masking were investigated for both monotic and dichotic conditions using white noise as the masking signal and a 1000‐cps probe signal. Results indicate that monotic backward masking occurs over intervals up to 50 msec while, for the dichotic condition, backward masking occurs for intervals as long as 15 msec. Less monotic forward masking is obtained for brief masking intervals and very little dichotic forward masking is observed. These findings are considered in relationship to other experimental results.

ISSN:0001-4966    

DOI:10.1121/1.1918253

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

Backward and forward masking of 500‐, 1000‐, and 4000‐cps probe tones were explored under monotic and dichotic listening conditions. Effect of probe frequency was found to vary with duration of the masking interval.

ISSN:0001-4966    

DOI:10.1121/1.1918254

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

Data on loudness estimates at 60, 200, 500, 1000, 5000, and 10 000 cps were continued at the University of Arkansas from 1933 to 1959. A recalculation of all data to 1950 indicated that fractional judgments required a smaller decibel change of intensity than the corresponding multiple loudness estimates. This new result, hereafter referred to as the directional dependency, accompanied by a provisional explanation, was recorded in theJournal of the Arkansas Academy of Sciencesin 1950, and reported together with certain additional experiments at the Second ICA Congress in June of 1956.Since reluctance to accept unanticipated results is considerable, a new approach to a series of experiments designed to explore this directional dependency was preceded by review of a possible dynamical explanation. The follow‐up experiments included the proposed dynamical explanation as a part of the experimental objective and included new methods in our laboratory for the recording of judgments.The results of the earlier series have been confirmed, but a satisfying explanation has not been established.

ISSN:0001-4966    

DOI:10.1121/1.1918256

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

Subjects were asked to center a noise presented via earphones, by adjusting a delay line controlling interaural time differences. Various noise correlations were employed ranging from 1.00 to 0.10. Even in the latter case, which represents a signal to noise difference of −9.5 dB the subjects were able to perform well above a chance level.

ISSN:0001-4966    

DOI:10.1121/1.1918257

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

Masking level differences obtained for 167 cps are presented. Some involved shifting the phase of the signal through various angles, and others, shifting the noise in interaural time. Where the experimental conditions are comparable to Hirsh's at 200 cps, the data agree very closely with his. The data obtained with various interaural time differences in the noise are shown to differ sharply from comparable data taken at 500 cps.

ISSN:0001-4966    

DOI:10.1121/1.1918258

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

Animal experiments have suggested the possibility that the compressional mode of bone conduction might produce a displacement of the cochlear partition, even when the cochlear windows and all other potential pressure outlets are closed. This assumption was found correct for the case of a cochlear model. It executed so‐called “distortional” vibrations, i.e., while its walls in one place moved inward, those in the other moved outward and vice versa. This mode of motion tends to keep constant the total volume of the enclosed incompressible fluids.The two perilymphatic spaces are known to differ in volume. Distortional motion causes the volume difference to alternate, thus producing compensatory displacements of the partition. This is in contrast to the effect upon the partition of the translatory and antiphasic movements of the cochlear windows in response to air‐conducted sound. When both windows are open, or only one is occluded, the displacement of the partition, due to bone‐conducted sound, represents the combined result of distortional and translatory motion.The generation of traveling waves, when input and output are distributed over the entire cochlear shell, as in bone conduction, is discussed in terms of general cochlear mechanics.

ISSN:0001-4966    

DOI:10.1121/1.1918259

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

The effective protection provided by arousal of the acoustic reflex against temporary threshold shift (TTS) at 4 kc from exposure to impulse noise was studied by comparing the rate of growth of TTS produced by 2‐min exposures to clicks of successively higher peak levels under two conditions: first, when the clicks were heard alone, and second, when each click was preceded at various intervals from 25 to 150 msec by a 1000‐cps 100‐dB pure tone presented to the contralateral ear. The results imply that the effective attenuation amounts to 1 dB at 25 msec, 5 dB at 62 msec, and 13 dB at 100 msec. Individual differences were large; some of the most slowly responding ears did not show significant protection until the delay reached 150 msec. The practical conclusion reached is that a reflex‐arousal stimulus to be used to protect gun crews should precede firing by 150 msec or more. In regard to theory, the results support the hypothesis that the value of the acoustic impedance of an ear at any instant is an accurate indicator of the protection provided by the middle ear muscles. However, there is also evidence that part of the protection may stem from a change, with reflex arousal, in the peak‐limiting characteristics of the middle ear.

ISSN:0001-4966    

DOI:10.1121/1.1918260

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP

摘要:

The measured absorption coefficients of acoustical materials are often misleading when the material is mounted in a manner which differs from the test procedure. It is suggested that the use of the energy reflection, absorption, and transmission coefficients of the material would obviate this difficulty.

ISSN:0001-4966    

DOI:10.1121/1.1918262

出版商:Acoustical Society of America    

年代:1962

数据来源: AIP