The auditory brainstem responses in patients with unilateral cochlear hearing loss.

The aim of our study is to analyze changes occurring in the auditory brainstem response (ABR) according to stimulus parameters in unilateral cochlear hearing loss cases. Twenty-nine cases (14 male, 15 female) with unilateral sensorineural hearing loss (SNHL) were investigated. All cases had cochlear SNHL on one side whereas normal hearing on the other side. All cases underwent ABR testing with varying stimulus intensity levels and stimulus repetition rates (SRRs). Results were compared and their correlation with audiogram shapes investigated. As stimulus intensity levels decreased on both ears, latencies expanded and amplitudes decreased in all traces of ABR. Latencies of ears with cochlear hearing loss were observed to be longer than those in normal ears. Responses to SRR increases were similar on both ears. Audiogram shapes should be taken into consideration while performing ABR in order to address asymmetric SNHL. The interpretation of ABR changes with various stimulus levels may provide a better understanding of cochlear pathologies associated with hearing loss in the future.