Evoked otoacoustic emissions in patients with Meniere's disease

Hypothesis: This study investigated whether otoacoustic emissions (OAEs) in patients with Meniere's disease show abnormal properties. Background: Patients with Meniere's disease experience vertigo. tinnitus, and hearing loss. OAEs are sounds generated in the inner ear. and their presence is associated with normal hearing. Methods: Click-evoked OAEs and distortion product OAEs were measured in 100 patients with Meniere's disease. Results: The incidence of the emissions in affected ears (56%) was lower than in unaffected (i.e., contralaterul) ears (85%). The mean emission amplitude in affected cars was also significantly lower (2.6 dB), and the mean amplitude in unaffected ears was lower than in normal-hearing cars (5.3 dB). These differences were likely caused by the hearing loss involved, Further, ears with OAEs clearly showed smaller hearing losses than cars without OAEs (24-dB difference). The average hearing loss showed correlations with the emission amplitudes. although this correlation was not very strong when plotted against the smallest hearing loss, a certain upper boundary for the emission amplitude was present, Also, the amplitude of click-evoked OAEs showed a considerable correlation with the largest of the three distortion product OAEs. Conclusion: OAEs in patients with Meniere's disease differed from those in normal-hearing ears but did not differ from those in non-Meniere's ears with equivalent hearing loss. This was best observed by computing emission amplitude with smallest hearing loss instead of mean hearing loss.