Role of harmonicity in counting and hearing out voices in polyphonic music: Effects of hearing loss.

Music plays an important role in many people's lives. While the effects of hearing loss on speech are well studied, its impact on music perception is less understood. To address this gap, the current study utilized polyphonic female vocal passages in an enumeration and a voice-tracking task to investigate how normal-hearing (NH) and hearing-impaired (HI) listeners with mild to moderate sensorineural hearing loss perceive individual voices in polyphonic music. We hypothesized that hearing loss would hinder listeners' ability to distinguish voices in music due to impaired frequency selectivity, but that inharmonicity, introduced separately into each voice, would impact HI listeners less, due to their potentially reduced sensitivity to inharmonicity and pitch. Results indicated that NH listeners outperformed HI listeners in the enumeration task, but that performance in the voice-tracking task was not significantly different between groups. Although inharmonicity degraded performance across tasks, particularly in the enumeration task, HI listeners were less affected than NH listeners, at least at higher voice numbers. Exploratory analyses showed modest influences of age and musicianship on HI listeners' performance in the enumeration task and provide promising avenues for future research. Overall, these findings point toward a task-dependent effect of hearing loss on music perception, impacting dense auditory scenes more severely, while leaving some ability to track a cued voice within polyphonic music. Taken together, these results may help inform future research exploring targeted interventions to support music listening for HI listeners.