EFFECT OF ASPIRIN ON TRANSIENTLY EVOKED OTOACOUSTIC EMISSIONS IN GUINEA-PIGS

Aspirin and other salicylates influence otoacoustic emissions (OAEs), but changes in transiently evoked OAEs (TEOAEs) following aspirin inta ke have not been studied experimentally. We examined the changes in TE OAEs, together with auditory brainstem responses (ABRs), in guinea pig s before and after the intravenous injection of aspirin (100 and 400 m g/kg). TEOAE power decreased slowly after the injection in a dose-depe ndent manner. Mean minimal values were detected 20 min after the injec tion of 100 mg/kg, and 40 min after the injection of 400 mg/kg. TEOAE power recovered slowly. These changes were paralleled by shifts in ABR thresholds. The magnitude of the decrease in the frequency components in the TEOAE frequency power spectrum was similar. In one guinea pig, TEOAE power returned to the pretreatment level 7 h after the injectio n. Findings support the results of in vitro studies that salicylates a ffect electromotility in isolated outer hair cells from guinea pig coc hlea.