Otoacoustic emissions and tinnitus in normal hearing

To compare cochlear outer hair cells function in normally hearing patients with and without tinnitus. Twenty four tinnitus patients were selected as a study group based on having normal hearing threshold levels in the frequency range between 750 to 6000 kHz. The control group consisted of 24 otologically normal subjects who have normal hearing threshold levels without tinnitus and were selected to match the study group by age and gender. Significant differences in distortion product otoacoustic emissions amplitude at P< 0.05 were found between the study group and the control group in the frequency range between 750 to 6000 Hz. There is an association between tinnitus and reduced distortion product otoacoustic emission amplitudes indicating reduced cochlear outer hair cells function