Comparisons of quality ratings for music by cochlear implant and hearing aid users

This study aimed to compare the quality ratings by cochlear implant (CI) and hearing aid (HA) users in response to musical sounds.

The ratings of 15 experienced adult Nucleus CI users (using the Advanced Combination Encoder (ACE) or Spectral Peak (SPEAK) strategy) were compared with those of 15 experienced adult HA users who met the audiological criteria for implantation. Additionally, nine subjects on the waiting list (WL) for an implant were tested before and after implantation. Three types of musical stimuli were used: single instruments, solo instruments with background accompaniment, and ensembles. For each of these categories, 12 different instruments or ensembles were presented four times each. Subjects were asked to provide a rating out of 10 according to how pleasant each extract sounded, with 10 being "very pleasant."

For the WL subjects, ratings provided after implantation were significantly higher than their preimplant ratings obtained when using HAs (p = 0.026). This was consistent with a trend observed from the experienced CI and HA groups, whereby the CI group provided higher ratings than the HA group for all three subtests, although the difference was not statistically significant. For all groups, single-instrument stimuli received significantly higher ratings than those involving multiple instruments (CI and HA subjects: p < 0.001; WL subjects: p = 0.034). With this research being part of a larger study in which identification testing of these stimuli had previously been conducted, significant correlations were also obtained between the subjects' ability to identify musical stimuli and the corresponding quality ratings (CI: rho = 0.325, p = 0.029; HA: rho = 0.491, p = 0.001).

The findings of this study suggest that although neither device enables highly satisfactory music appreciation, the CI users judged music to sound more pleasant than the HA users (who had similar levels of hearing impairment). Also, all subject groups appraised music that involved multiple instruments to sound less pleasant, on average, than music played by single instruments.