In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 44, No. 1_Supplement ( 1968-07-01), p. 363-364
Abstract:
The nulling technique described in the preceding abstract has been used to study the responses of cochlear nerve fibers with low characteristic frequency (CF) to combination click stimuli. For a given fiber the intensities of two clicks separated by some multiple of half the period of the fiber's CF can be adjusted to null a particular peak in the corresponding PST histogram. If the two clicks are assumed to produce identical, linearly superposing click excitation functions (CEF's), the relative amplitudes of adjacent peaks of the CEF can be obtained from nulls in the PST histograms obtained with a click separation of half the period of the CF of the fiber. The relative amplitudes of peaks separated by k half-periods can be obtained indirectly from these measurements or by direct measurement using the nulling technique with click separations of k half-periods. The results obtained by these two methods do not agree and hence are inconsistent with the assumption of linear superposition of CEF's. In all cases, the nulls obtained at longer click separations require smaller intensities of the second click (from a few decibels to more than 25 dB) than would be expected for linear superposition of the CEF's. Furthermore, for a given fiber, the deviation from linearity increases with increased second click delay (delays range from 0.3 to 4 msec). Thus it seems appropriate to term this effect a temporal nonlinearity. These measurements point out a fundamental defect in existing models of the peripheral auditory system, none of which, to the best of our knowledge, include the effect of such a temporal nonlinearity. [This investigation was supported by PHS research grants from the National Institutes of Health.]
Type of Medium:
Online Resource
ISSN:
0001-4966
,
1520-8524
Language:
English
Publisher:
Acoustical Society of America (ASA)
Publication Date:
1968
detail.hit.zdb_id:
1461063-2
