Nonlinear wave propagation in the cochlea with feed-forward and feed-backward

A nonlinear active feed-forward/feed-backward mechanism exciting the basilar membrane (through the activity of the outer hair cells) has been highlighted in previous works as responsible for remarkable amplification in the cochlea. A saturation phenomenon in the transduction process has further been pointed out as a significant nonlinear feature. In this work, a candidate nonlinearity is accounted for through the stretching effect in a one-dimensional string model of the basilar membrane. An asymptotic treatment of the partial differential equations of motion-including the space-delayed terms represented by the feed-forward and feed-backward outer hair cells forces-shows some properties of the nonlinear vibrational behavior of the basilar membrane which may pave the way to understanding some experimentally observed nonlinear features. © Springer Science + Business Media B.V. 2011.