[Frequency selectivity of the normal guinea pig cochlea and in experimental hearing loss]

The frequency selectivity of the cochlea was measured in pigmented guinea pigs with implanted electrodes using simultaneous masking paradigm. In animals with experimentally induced deafness, AP tuning curves are broadened by a factor of 2-3 as compared with normal animals. The deterioration of frequency selectivity is thought to correlate with extent of the outer hair cells loss. The deterioration of threshold and tuning properties of the cochlea seem to be induced by the loss of the functional integrity of the outer hair cells.