Summary
Rhinolophus ferrumequinum compensates for Doppler shifts and keeps the frequency of the CF-portion of echoes constant at a reference frequency. The bat's cochlea is specialised for the detection of sounds in a narrow range including this reference frequency. The threshold curve of the N1-on (summated activity of primary auditory neurons evoked at the onset of a tonal stimulus) has a sharp notch about 24–30 dB deep which is exactly tuned to the reference frequency. N1-off is most prominent at stimulus frequencies 0.5–1 kHz below the reference frequency. In this frequency range the envelopes of the CM (cochlear microphonics) have slower rise and decay times than the stimulus envelopes. A comparison of our physiological data with the morphological data of Bruns (1976a, b) leads to the suggestion that the cochlea acts as a narrowly-tuned mechanical filter which is responsible for sharp tuning of the CM, N1-on and N1-off threshold curves.
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Bruns, V.: Peripheral auditory tuning for fine frequency analysis by the CF-FM bat,Rhinolophus ferrumequinum. I. Mechanical specializations of the cochlea. J. Comp. Physiol.106, 77–86 (1976)
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, 87–97 (1976)
Grinnell, A.D.: Rebound excitation (off-responses) following non-neural suppressioryn the cochlea of echolocating bats. J. Comp. Physiol.82, 179–194 (1973)
Machmerth, H., Theiss, D., Schnitzler, H.-U.: Konstruktion eines Luftschallgebers mit konstantem Frequenzgang im Bereich von 15–130 kHz. Acustica34, 81–85 (1975)
Neuweiler, G.: Neurophysiologische Untersuchungen zum Echoortungssystem der Großen HufeisennaseRhinolophus ferrumequinum Schreber, 1774. Z. vergl. Physiol.67, 273–306 (1970)
Neuweiler, G., Schuller, G., Schnitzler, H.-U.: On- and off-responses in the inferior colliculus of the greater horseshoe bat to pure tones. Z. vergl. Physiol.74, 57–63 (1971)
Schnitzler, H.-U.: Die Ultraschall-Ortungslaute der Hufeisen-Fledermäuse (Chiroptera-Rhinolophidae) in verschiedenen Orientierungssituationen. Z. vergl. Physiol.57, 376–408 (1968)
Schnitzler, H.-U.: Control of Doppier shift compensation in the greater horseshoe batRhinolophus ferrumequinum. J. Comp. Physiol.82, 79–92 (1973a)
Schnitzler, H.-U.: Die Echoortung der Fledermäuse und ihre hörphysiologischen Grundlagen. Fortschr. Zool.21, 136–189 (1973b)
Schnitzler, H.-U., Schuller, G., Neuweiler, G.: Antworten des Colliculus inferior der FledermausRhinolophus euryale auf tonale Reizung. Naturwissenschaften58, 617 (1971)
Schuller, G., Beuter, K., Schnitzler, H.-U.: Response to frequency shifted artificial echoes in the bat,Rhinolophus ferrumequinum. J. Comp. Physiol.89, 275–286 (1974)
Simmons, J.A.: Response of the Doppler echolocation system in the bat,Rhinolophus ferrumequinum. J. acoust. Soc. Amer.56, 672–682 (1974)
Suga, N., Neuweiler, G., Möller, J.: Peripheral auditory tuning for fine frequency analysis by the CF-FM bat,Rhinolophus ferrumequinum. IV. Properties of peripheral auditory neurons. J. Comp. Physiol.106, 111–125 (1976)
Suga, N., Simmons, J.A., Jen, P.H.-S.: Peripheral specializations for fine frequency analysis of Doppler-shifted echoes in CF-FM batPteronotus parnellii. J. exp. Biol.63, 161–192 (1975)
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Supported by Deutsche Forschungsgemeinschaft, grant No. Schn 138/1-4, Stiftung Volkswagenwerk, grant No. 111858 and U.S. National Science Foundation (GB 40018 and BMS 75-17077).
We thank A.D. Grinnell for discussion and W. Hollerbach for technical assistance.
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Schnitzler, H.U., Suga, N. & Simmons, J.A. Peripheral auditory tuning for fine frequency analysis by the CF-FM bat,Rhinolophus ferrumequinum . J. Comp. Physiol. 106, 99–110 (1976). https://doi.org/10.1007/BF00606575
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DOI: https://doi.org/10.1007/BF00606575