Musicians from classical orchestras bear the risk of hearing impairments due to their exposure to loud music. Sound intensities during rehearsals or on the stages often exceed 100 dB SPL [Emmerich et al., 2008]. Only a minority of the musicians regularly uses otoplastics or other types of hearing protectors. The refusal often is based on the assumption that wrong or mistuned sounds could not be percepted or playing of the own instruments is impaired resulting in a growing number of hearing impaired professional musicians when playing for 10 years or longer in a classical orchestra.

We investigated the influence of custom-designed otoplastics on auditory evoked potentials (AEP) and compared these data with the perception (intentional vs. non-intentional) of piano chords with different frequencies. 16 normal-hearing musicians (age 25–41, 7 females) and 21 hearing impaired musicians participated in our study. The control groups consisted of 20 hearing impaired workers from the beverage industry at same ages and of 20 students from Medical Faculty (non-musicians). Stimuli were series of in-tune and either more (-30 cent) or less (-12 cent) mistuned piano chords. 200 stimuli were presented randomly according to the oddball paradigm (in-tune to mistuned = 4:1) in one series at an intensity of 65 dB SPL either while the normal hearing musicians used their otoplastics or not. In another series stimulus intensity was diminished to 45 dB SPL and no otoplastics were used. Source localization studies (in-tune vs. mistuned chords) were performed using auditory evoked magnetic fields (AEF) in normal hearing musicians and non-musicians.

Our results show that professional musicians in all series of stimulation observed the mistuned stimuli. Both the observation of the recorded AEP as well as the self-monitoring of the musicians (pressing a button when noticing a mistuned chord) confirmed these data. Highly significant differences existed regarding magnitude and duration of mismatch negativity to mistuned chords between musicians and non-musicians. The hearing impaired professional musicians had still larger mismatch negativities than the hearing impaired non-musicians. We assume that learning during profession plays an important role and seems to be able to compensate a part of the hearing deficit unless stimulation is performed with profession-specific stimuli.

These data are relevant for the development of noise-induced hearing damage due to profession-specific acoustic overload and the development of adequate hearing protectors (custom-made otoplastics) for professional musicians.

Reference: Emmerich,E.; Rudel,L.; Richter,F. Is the audiologic status of professional musicians a reflection of the noise exposure in classical orchestral music? Eur. Arch. of Otorhinolaryngol. 265 753–758, 2008