Automatic Gain Control in Cochlear Mechanics
Measurements of basilar membrane motion show that the cochlea has a strong compressive nonlinearity over a wide range of sound intensities, even down to low intensities where the system might be expected to be linear. Many models of cochlear hydrodynamics and micro-mechanics ignore this strong nonlinearity in order to be able to apply lincar systems concepts, sometimes resulting in inappropriate interpretations of cochlear function. We propose a modeling approach based on explicitly recognizing the purpose of the strong nonlinearity as an automatic gain control (AGC) that serves to map a huge dynamic range of physical stimuli into the limited dynamic range of nerve firings.
KeywordsBasilar Membrane Tuning Curve Automatic Gain Control Probe Tone Active Gain
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