Distortion product otoacoustic emissions in tinnitus cases with normal hearing level

Objective To investigate the clinical implications of distortion product of otoacoustic emissions(DPOAE) in tinnitus cases with normal hearing level. Methods DPOAE was detected and analyzed in 26 tinnitus cases (46 ears) with normal hearing level by ILO96 Otodynamic Analyzer. Results In this group of cases, the rate of normal DPOAE was 63.04%(29/46 ears) and the one of abnormal DPOAE was 36.96%(17/46 ears).Furthermore,the frequencies of tinnitus were basically coincident with the range of frequency distribution showing amplitude decreasing in 9 ears(52.94%) among the cases with abnormal DPOAE,while 8 ears (47.06%) showed incomplete coincident but approaching in the distribution of frequent range in this aspect. Conclusions Detection of DPOAE for tinnitus cases with normal hearing level may be helpful to detect the minimal injury in cochlea early and holds significant clinical implications to guide clinical treatment and to prevent cochlear lesions from developing earlier.