Pitch expertise is not created equal: Cross-domain effects of musicianship and tone language experience on neural and behavioural discrimination of speech and music.

Psychophysiological evidence supports a music-language association, such that experience in one domain can impact processing required in the other domain. We investigated the bidirectionality of this association by measuring event-related potentials (ERPs) in native English-speaking musicians, native tone language (Cantonese) nonmusicians, and native English-speaking nonmusician controls. We tested the degree to which pitch expertise stemming from musicianship or tone language experience similarly enhances the neural encoding of auditory information necessary for speech and music processing. Early cortical discriminatory processing for music and speech sounds was characterized using the mismatch negativity (MMN). Stimuli included 'large deviant' and 'small deviant' pairs of sounds that differed minimally in pitch (fundamental frequency, F0; contrastive musical tones) or timbre (first formant, F1; contrastive speech vowels). Behavioural F0 and F1 difference limen tasks probed listeners' perceptual acuity for these same acoustic features. Musicians and Cantonese speakers performed comparably in pitch discrimination; only musicians showed an additional advantage on timbre discrimination performance and an enhanced MMN responses to both music and speech. Cantonese language experience was not associated with enhancements on neural measures, despite enhanced behavioural pitch acuity. These data suggest that while both musicianship and tone language experience enhance some aspects of auditory acuity (behavioural pitch discrimination), musicianship confers farther-reaching enhancements to auditory function, tuning both pitch and timbre-related brain processes.