Some implications of nonlinear passive models of spontaneous otoacoustic emissions

Abstract

The nonlinear passive cochlear model of M. Furst and M. Lapid [J. Acoust. Soc. Am. 84, 222–229 (1988)] has recently been criticized by Wit [J. Acoust. Soc. Am. 85, 2217 (1989)] on grounds that this model is not able to account for the observed statistical [Bialek and Wit, Phys. Lett. A 104, 173–178 (1984)] and external‐tone entrainment [Long et al., Basic Issues of Hearing, edited by H. Duifhuis et el. (Academic, London, 1988), pp. 93–100] properties of spontaneous otoacoustic emissions. The argument of Wit and the response to it by M. Furst [J. Acoust. Soc. Am. 85, 2218–2220 (1989)] are critically examined. On the basis of numerical simulations and exact solutions [Caughey and Payne, Int. J. Non‐Linear Mech. 2, 125–151 (1967)] of the Fokker‐Planck equation for stochastically driven nonlinear passive oscillators, it is concluded, in agreement with Wit, that nonlinear passive cochlear models of the type used by Furst and Lapid are not able to adequately describe the observed behavior of spontaneous otoacoustic emissions. [Work supported by NIDCD.]