Active traveling wave in the cochlea.

A sound stimulus entering the inner ear excites a deformation of the basilar membrane which travels along the cochlea towards the apex. It is well established that this wavelike disturbance is amplified by an active system. Recently, it has been proposed that the active system consists of a set of self-tuned critical oscillators which automatically operate at an oscillatory instability. Here, we show how the concepts of a traveling wave and of self-tuned critical oscillators can be combined to describe the nonlinear wave in the cochlea.