Amplitude fluctuations of spontaneous otoacoustic emissions caused by internal and externally applied noise sources.

The simplest description for the generator of a spontaneous otoacoustic emission (SOAE) is that of a single (isolated) limit-cycle oscillator. Evidence is given that this description is too simple. And it is concluded that study of systems of coupled oscillators is needed to obtain more insight in the processes that generate SOAEs. Part of this conclusion is based on the study of properties of coupled electronic Van der Pol oscillators.