Distortion product otoacoustic emission in the diagnosis of sensory hearing loss

AIM To study the changing properties of distortion product otoacoustic emissions (DPOAE) in sensory hearing loss, and to discuss the significance of DPOAE in the diagnosis of sensory hearing loss. METHODS The DPOAEs were examined in 167 ears with cochlear hearing loss and the DPOAE gram and I/O functions were recorded. RESULTS For all auditory frequencies, the maximum correlation coefficient existed at one particular distortion product frequency,the correlationcoefficients were 0.44～0.85, higher than those of the adjacent frequencies. The DPOAE gram could show the frequency region of hearing loss in cochlea. The incidence and amplitude of DPOAE decreased, and the detection threshold increased with the increase of hearing loss. Compared with normal ears, the slopes of I/O function were high. CONCLUSION DPOAE had good frequency specific, could precisely reflect the frequency region of affected cochlea and reflect the change of function state to some extent, and had great clinical application values in evaluating the function state of cochlea and in the diagnosis of ear diseases.