Modifications of the nonlinearity of the cochlear microphonic responses produced by noise exposure in the guinea pig

Cochlear microphonics (CM) were recorded with differential electrodes from several locations in the guinea pig cochlea. Input-output curves and amplitude-frequency curves were plotted before and after short exposures to intense noise. In addition to amplitude losses, important changes in the intensity functions resulted in a decrease of the nonlinearity and in a modification of the frequency response. The mechanisms producing these alterations are discussed.