CHARACTERISTICS OF DPOAE AUDIOGRAM IN TINNITUS PATIENTS

To investigate cochlear activity in tinnitus, the DPOAE (distortion pr oduct otoacoustic emission) audiograms (DP-gram) of tinnitus patients were measured. Nine tinnitus patients (15 ears) with normal hearing an d 55 tinnitus patients (75 ears) with hearing impairment were included in this study. Significant decreases in DPOAE amplitude over a limite d frequency range were observed in 93.3% of the normal hearing tinnitu s group and in 96% of the hearing-impaired tinnitus group. The average d DP-gram of the normal hearing tinnitus group was significantly diffe rent from that of the normal subjects (repeated-measures ANOVA, P < 0. 01). These results imply that tinnitus may be evaluated objectively by DPOAE.