(PP505) Auditory Electrophysiological and Perceptual Measures in Student Musicians with High-Noise Exposure

Abstract:

Objective: This study aimed to determine: (a) the effects of noise exposure background (NEB) on the peripheral and central auditory system functioning, and (b) the effect of noise exposure history on speech recognition in noise in student musicians with high NEB.

Methods: 19 student musicians with high NEB and 20 non-musician students with low NEB completed an audiological test battery which comprised both objective and subjective tests to assess auditory system functioning.
Outcomes: The NEB was negatively associated with word recognition in noise performance. No effect of NEB was found on the amplitude of P300 and ABR wave I amplitude.

Summary: 

Rationale: To determine: (a) the effects of noise exposure on the peripheral and central auditory nervous system (CANS) functioning, and (b) the effect of noise exposure history on speech recognition in noise in student musicians with high noise exposure background (NEB).


Design: To examine for the signs of cochlear nerve damage and its effect on speech in noise abilities, we recruited 19 student musicians with self-reported high NEB and 20 non-musician students with self-reported low NEB. A test battery was administered that consisted of two sets of procedures: (a) electrophysiological tests including auditory brainstem responses (ABRs) at three different stimulus rates (11.3Hz, 51.3 Hz, and 81.3 Hz), P300, and distortion product otoacoustic emissions, and (b) behavioral tests including conventional and extended high-frequency audiometry, Consonant-Vowel Nucleus-Consonant (CNC) word test and AzBio sentence test for assessing speech in noise abilities at -9, -6, -3, 0, and +3 dB signal to noise ratios (SNRs).


Results: The NEB was negatively associated with the performance on the CNC test at all five SNRs.  A negative association was found between NEB and performance on the AzBio test at 0 dB SNR. No effect of NEB was found on the amplitude and latency of P300 and ABR wave I at all three stimulus rates. No significant difference was found in DPOAEs and hearing thresholds between the two groups.


Conclusion: Student musicians showed significantly poorer performance on word recognition in noise tasks than non-musician students. However, there was no negative relationship between NEB and electrophysiological measures such as amplitude and latency of P300 and ABR wave I. These results suggest that ABR offers limited sensitivity to synaptopathy in humans, perhaps because of higher measurement variability due to other factors/sources or due to the limited contribution of auditory nerve fibers reported to be associated with noise-induced synaptopathy. The findings of this study do not support the notion that poorer word recognition in noise among student musicians with normal audiograms is caused by noise-induced synaptopathy.
Potential Impact: This study investigates the condition of possessing normal hearing while simultaneously struggling with auditory comprehension in difficult listening environments. By identifying common features among this population, the field of audiology can better understand the physiology of such deficits and the best way to manage this type of deficits.