Interactions Among Multiple Spontaneous Otoacoustic Emissions

Evidence has recently been obtained (Burns et al., 1984) for several interactions among spontaneous otoacoustic emissions (SOAEs) including intermodulation distortion products, mutual suppression, and noncontiguous-linked SOAEs which apparently share energy between two quasi-stable states. In this paper, we give an updated record of our findings on intermodulation distortion products and linked emissions, and give evidence that the former tend to occur when a distortion product frequency is close to that of a cochlear resonance. Computer simulations of the interactions among van der Pol oscillators, which represent nonlinear active elements in a simplified cochlear model, appear to qualitatively account for some of the observed features of SOAE interactions.