Publication:

Effects of brief exposure to loud music on otoacoustic emissions and auditory brainstem responses

Background Research on noise induced hearing loss pathophysiology has recently focused on synapses rather than outer hair cells, following relevant evidence from animal studies. Findings from human studies, mainly targeting on effect of chronic exposure are controversial. Aim of this study is to investigate the immediate effect of noise exposure to synaptic function with use of ABR and DPOAEs.

Methods Ten participants with normal hearing levels underwent DP-gram between 1 and 6 KHz and ABR at 90dB and click rates 33/sec and 44/sec before and after exposure to standardized music. Four of them were professional musicians and six were controls. Material for reliable and constant exposure to music was created, consisting of 56 wav files with music with a total duration of 2.5 hours. Files were presented in stable dB SPL levels and absolute control of dB SPL levels to ear phones was ensured. Subjects were asked to listen to music of their preference in maximum for 30 minutes. Patients exceeding 83 dB SPL maximum comfortable levels were eligible for the study.

Results Statistically significant differences were observed before and after exposure to music for all SNRs from 1.5 to 6 KHz. Changes were similar between musicians and non-musicians. No differences were observed in ABR latencies and amplitudes in any of the waveforms before and after noise exposure.

Conclusions A reliable technique has been developed for standardized exposure to loud sounds in humans, which can be used in future studies. Exposure to music induced decrease in DPOAE SNRs.