Compound action potential input-output decruitment. Effect of topically applied antiseptics.

The ototoxic effect of povidone-iodine antiseptics topically applied to the chinchilla round window was examined with particular emphasis on the action potential (AP) input-output function at 2 and 4 kHz. A group of chinchillas exhibited a marked elevation of AP threshold at 8 and 12 kHz, with only a slight threshold elevation at 2 and 4 kHz. A distinct decruitment (less than normal growth of response with increasing sound intensity) of the AP input-output function was, however, found at the lower frequencies. There are implications of an ototoxically induced high-frequency hearing loss on speech frequencies.