Altered Paired-Click Auditory Brainstem Responses in Normal-Hearing Young Adults With Frequent Loud Sound Exposure

This study investigated differences in auditory brainstem responses (ABRs) using the paired-click paradigm between young adults frequently exposed to loud sounds and those not. Young adults with normal hearing were divided into two groups: an exposed group (n = 23), who were frequently exposed to loud sounds through music practice, and a control group (n = 21). Sound exposure levels (measured via smartwatch), hearing thresholds (0.125-16 kHz), distortion product otoacoustic emission (DPOAE) magnitudes, word intelligibility, and ABRs to single and paired clicks were obtained. For paired-click ABRs, root mean square values for the post-wave I response delayed from the wave I peak (RMS_post-w1) were calculated for second-click responses. The exposed group exhibited higher sound exposure levels than the control group. Despite similar hearing thresholds, DPOAE magnitudes, wave I peak amplitudes and wave I/V amplitude ratio, the exposed group showed significantly lower RMS_post-w1 values for second-click responses than the control group. No significant group difference was observed in word intelligibility. The results showed that frequent loud sound exposure may induce peripheral auditory changes consistent with cochlear synaptopathy (CS). This suggests that the paired-click stimulation paradigm may offer a way of detecting noise-induced CS.