Distortion-Product and Transient-Evoked Otoacoustic Emissions Before and After Noise Exposure During Drummer Rehearsals

Abstract

Objective: This study aimed to evaluate sound exposure levels in drummers and analyses changes in distortion product otoacoustic emissions (DPOAEs), transient-evoked otoacoustic emissions (TEOAEs), and the contralateral suppression (CS) of otoacoustic emissions (OAEs) before and after a controlled rehearsal session. Method: This study had a pre-experimental design and included volunteer drummers. The subjects responded to surveys to explore general hearing health and musical practice habits. Hearing tests were performed under controlled conditions: DPOAEs and TEOAEs were used to determine the activity of the outer hair cells (OHCs), and the CS of DPOAEs and TEOAEs were applied as indicators of the functioning of the medial olivocochlear efferent system. The drummers subsequently performed freely for 20 min, and their noise exposure was measured. Immediately after completing the rehearsal, the volunteers repeated the tests. Descriptive analysis and comparisons of the tests were used to examine the differences in the response of DPOAEs and TEOAEs. Results: Eighteen drummers were exposed to noise levels above 103 dBA, with over 60% not using hearing protection. Statistically significant changes (P < 0.05) in DPOAE amplitudes were found at 4000, 6000, and 10,000 Hz for the right ear and at 1000 and 6000 Hz for the left ear. For TEOAEs, significant differences (P < 0.05) occurred at 2000 (right ear) and 2800 Hz (left ear). Asymmetries in cochlear function and CS were also observed, suggesting functional differences between ears that were possibly linked to chronic noise exposure. Conclusion: The findings underscore the cochlear susceptibility to high frequencies and emphasize the importance of preventive strategies in this musician population.