On mechanical preprocessing in the cochlea: the three great hearing theories combined.
Since otoacoustic emissions were discovered, the old idea of a second (active) filter in the cochlea has been pursued with considerable dedication. In this contribution a concept explaining the action of the second filter is presented, which is derived from high-frequency resonance: The outer hair cells are excited when the traveling wave breaks rather than when it reaches its peak amplitude. They vibrate at a much higher frequency, i.e. their mechano-electrical resonant frequency. The amplitude of the exciting stimulus is very small, but in keeping with the chaos theory it is amplified by self-organization to a level sufficient for physiologic excitation. This concept helps to explain the hitherto unexplained frequency changes of spontaneous otoacoustic emissions.
Fritze
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ENT Department, University of Vienna Medical School, Austria.
D000818:Animals; D001307:Auditory Perception; D003051:Cochlea / Q000502:physiology*; D003198:Computer Simulation; D007758:Ear, Inner / Q000502:physiology; D004432:Ear, Middle / Q000502:physiology; D006309:Hearing; D008954:Models, Biological; D008959:Models, Neurological