Abstract
Communicative auditory signals convey structure through spectral and temporal cues. Individuals’ abilities to perceive these cues vary widely, and yet most people comprehend music and speech easily. How? Here we investigated whether degeneracy – multiple cues performing the same function – makes music and speech robust to such individual differences. We tested a model population with a severe deficit for perception of pitch but not duration (congenital amusics) and matched controls on speech prosody and music perception tasks. Although amusics were impaired when only pitch cues were available, they perceived speech and music normally when both cues were present. Moreover, in a separate fine-grained cue-weighting prosodic perception task, amusics down-weighted their unreliable channel (pitch) and up-weighted their reliable one (duration) compared to controls. The results suggest that music and speech exploit degeneracy to ensure message transmission, and that individual listeners in turn weight auditory dimensions advantageously across degenerate channels.