FREQUENCY-DEPENDENCE OF ACOUSTIC DISTORTION PRODUCTS IN A LOCALLY ACTIVE MODEL OF THE COCHLEA

In two-tone experiments it has been shown that acoustic distortion pro ducts are ''tuned'' as a function of primary frequency ratio, that is, at a certain frequency ratio a maximum in emission occurs. Several au thors maintain that this ''tuning'' is caused by band-pass filtering o f the distortion products as they are coupled back to the basilar memb rane. In this paper one possible other cause for this type of tuning i s brought to light. It is shown that the same kind of ''tuning'' is pr esent in a locally active cochlea model without such a filtering of di stortion products. In this view ''tuning'' becomes evident because, wh en the frequency ratio is near unity, the primary components tend to s uppress one another, and suppress the DP, too. (C) 1997 Acoustical Soc iety of America.