Kossl, M and Vater, M (1996) Further studies on the mechanics of the cochlear partition in the mustached bat .2. A second cochlear frequency map derived from acoustic distortion products. HEARING RESEARCH, 94 (1-2). pp. 78-86. ISSN 0378-5955,
Full text not available from this repository.Abstract
It has been proposed that acoustic 2f1-f2 distortions reflect the frequency characteristics of a secondary cochlear filter mechanism (Brown et al., 1992; Allen and Fahey, 1993). This concept was used to construct a second cochlear frequency, f1 was varied and the frequency ratio f2/f1 determined that produced maximum levels of the 2f1-f2 distortion (best ratio). The second cochlear frequency map was derived by plotting the distortion frequency that corresponded to the best ratio f2/f1 against the cochlear place of f2 which was obtained from the HRP-frequency that corresponded to the best ratio f2/f1 against the cochlear place of f2 which was obtained from the HRP-frequency map of Pteronotus (Kossl and Vater, 1985b). Minimum best ratio of 1,0005 and hence practically identical characteristic frequencies of the putative tuning of basilar membrane (HRP) and TM (2f1-f2) were found at about 45% distance from the base, a point at which 62 kHz are represented on the BM. This frequency is associated with strong cochlear resonance and large evoked and spontaneous otoacoustic emissions. Between 45% and 20% distance from the base, the basilar membrane (BM) tuning progressively increases to about 70 kHz whereas the calculated TM tuning remains constant at a frequency close to 62 kHz. The range of constant TM tuning coincides with the sparsely innervated cochlear region of Pteronotus where BM thickness is maximal and TM mass and limbal attachment are reduced (Vater and Kossl, 1996). We suggest that here the TM oscillates strongly at 62 kHz and may carry most of the energy of cochlear resonance which is transferred into movement of the organ of Corti at and apical to the 45% location where the Bm is tuned to 62 kHz.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PTERONOTUS-PARNELLII; BASILAR-MEMBRANE; INNER-EAR; 2F1-F2; SUPPRESSION; EMISSIONS; NUCLEUS; HUMANS; MODEL; TONES; otoacoustic emission; tectorial membrane; distortion product; cochlear resonance |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:35 |
| URI: | https://pred.uni-regensburg.de/id/eprint/51733 |
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