Music perception with cochlear implants

Abstract

The Mu.S.I.C. test covers 8 important aspects of music perception: pitch, rhythm, instrument identification, melody and chord differentiation, detection of the number of instruments, emotional impact and dissonance rating. This test battery was used to obtain an initial insight into the musical perception of unilateral, bilateral, EAS and bimodal CI users. For this study a subset of files from each subtest was presented. Group analysis could be performed for the unilateral group (n=31) vs 64 normal hearing subjects (NH). For the other groups (EAS n=15, bilateral = 7) a matched triplet analysis was performed vs. NH and unilateral implant users. The matching was performed according to age and musical experience before hearing loss as assessed in the MuMu questionnaire. There was no difference between any of the groups for rhythm discrimination, dissonance and emotion rating. Unilateral subjects scored significantly worse than NH in all the other subtests. EAS users scored the same as NH for pitch, chord and melody differentiation and worse than NH and similar to unilaterally implanted subjects in the instrument detection and differentiation tasks. Testing without the hearing aid in EAS users with unchanged setting of the speech processor did not lead to a significant deterioration of the results. In bilateral users we found no significant difference when compared to normal hearing subjects. Their results did not decline significantly when the "worse ear" was switched off. For none of the patients groups correlations were found between performance in any of the subtests with age at implantation, duration of implant use or musical experience before hearing loss or after implantation. Residual hearing did not influence the overall results in the EAS group. The results of the EAS users and the bilaterally implanted patients suggest that biological factors play a crucial role in music perception via cochlear implants