Abstract
The basilar membrane (BM) in the greater horseshoe bat has a peculiar thickness and width profile, which suggests that BM-stiffness in the basal half turn is more than one order of magnitude greater than in the second half turn and more apically. The transition is quite abrupt.
Motivated by new data on the cochlear frequency map we analyse the possibility that the stiffer basal half turn acts as an acoustic interference filter. Its increased stiffness and impedance transitions at the stapes and at the transition mentioned, make this a feasible mechanism. We propose that 2¼ wavelengths of the reflected call frequency of the echolocating bat match the length of the interference filter. Using a scaled version of the middle ear description given by Matthews (1980) and linear, passive, long-wave, 1-dimensional cochlear mechanics we analyse the effect of the interference filter and compute the tympanic membrane input impedance. Experimental data on the latter (Wilson and Bruns, 1983a) are interpreted in terms of the proposed mechanism: fine structure in the input impedance appears to reflect the interference filter passbands.
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References
Bruns, V., “Peripheral Auditory Tuning for Fine Frequency Analysis by the CF-FM Bat Rhinolophus ferrumequinum. I. Mechanical specialization of the cochlea,” J.comp.Physiol. 106, pp. 77–86, 1976a.
Bruns, V., “Peripheral Auditory Tuning for Fine Frequency Analysis by the CF-FM Bat Rhinolophus ferrumequinum. II. Frequency mapping in the cochlea,” J.comp.Physiol. 106, pp. 87–97, 1976b.
Matthews, J.W. Mechanical modeling of nonlinear phenomena observed in the peripheral auditory system. Doct.diss. Washington Univ., St Louis MO, 1980.
Neuweiler, G., Bruns, V. and Schuller, G., “Ears adapted for the detection of motion, or how echolocating bats have exploited the capacities of the mammalian auditory system,” J.Acoust.Soc.Am. 68, pp. 741–753, 1980.
Vater, M., Feng, A.S. and Betz, M., “An HRP-study of the frequency map of the horseshoe bat cochlea: Morphological correlates of the sharp tuning to a narrow frequency band,” J.comp.Physiol. in press 1985.
Wilson, J.P. and Bruns, V., “Middle-ear mechanics in the CF-bat Rhinotophus ferrumequinum,” Hearing Research 10, pp. 1–13, 1983a.
Wilson, J.P. and Bruns, V., “Basilar membrane tuning properties in the specialised cochlea of the CF-bat Rhinolophus ferrumequinum,” Hearing Research 10, pp. 15–35, 1983b.
Zwislocki, J., “Wave motion in the cochlea caused by bone conduction,” J.Acoust.Soc.Am. 25, pp. 986–989, 1953.
Zwislocki, J.J., “Sharp vibration maximum in the cochlea without wave reflection,” Hearing Research 9, pp. 103–111, 1983.
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© 1986 Springer-Verlag Berlin Heidelberg
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Duifhuis, H., Vater, M. (1986). On the Mechanics of the Horseshoe Bat Cochlea. In: Allen, J.B., Hall, J.L., Hubbard, A.E., Neely, S.T., Tubis, A. (eds) Peripheral Auditory Mechanisms. Lecture Notes in Biomathematics, vol 64. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-50038-1_12
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DOI: https://doi.org/10.1007/978-3-642-50038-1_12
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