Mathematical modeling of cochlear mechanics.

The recent discovery of oto-acoustic emissions [see Zurek, J. Acoust. Soc. Am. 78, 340-344 (1985)] and the newer measures of the micromechanics of the inner ear have generated renewed interest in quantitative descriptions of the biomechanics of the cochlea. Active elements (mechanical force generators) are thought to be essential for producing the high sensitivity and sharp tuning typically associated with normal cochlear function. A mechanical model with active elements is described which can simulate basilar membrane displacements with neural-like tuning and peak amplitudes of about 1 nm at the threshold of hearing. In addition, such models might help explain the source of oto-acoustic emissions. The paper describes the power of the recent attempts at providing quantitative descriptions and predictions of the mechanics of the cochlea.