Congenital Amusia and Tone Merger: Perception and Production of Lexical Tones in Hong Kong Cantonese

Congenital amusia is a disorder reported to affect one’s pitch processing in both music and language domains, resulting in an impaired discrimination of native lexical tones. Tone merging has been observed in native speakers of Hong Kong Cantonese, where some speakers confuse certain tone pairs in perception and/or production. Existing studies have only investigated the two groups separately, leaving a gap which concerns whether amusics’ profile is comparable to mergers’. The current study bridges the gap by directly comparing amusics and mergers in their ability to discriminate musical and lexical tones, plus their lexical tone production profile. Results revealed that mergers were intact in musical pitch perception and highly selective in lexical tone confusion. In contrast, amusics exhibited low sensitivity to all lexical tone pairs, and a dissociation between lexical tone perception and production. Preliminary findings suggest that congenital amusia and tone merging are inherently different.