The effects of absolute pitch ability and musical training on lexical tone perception

The relationship between processing of speech and music was explored here via the linguistic vehicle of lexical tone. People with amusia have been found to be impaired on linguistic tasks; we examined whether absolute pitch (AP) possessors have an advantage on linguistic tasks. Participants were 3 groups of monolingual Australian-English speakers: non-AP musicians (musically-trained individuals who did not possess AP), AP musicians (musically-trained individuals who were AP possessors), and non-musicians (no musical training). Perceptual discrimination was tested in an AX same-different task for lexical tones presented in three contexts: normal Thai speech, low-pass filtered speech tones, and violin, with processing level manipulated via variation of the interstimulus interval (ISI). Non-musicians showed attenuated pitch discrimination of tones in speech, suggesting speech specialisation. On the other hand, all musicians showed greater accuracy, faster reaction times and less variation in accuracy across stimulus types than non-musicians. Importantly, AP musicians showed greater accuracy than non-AP musicians in the speech context, implying a domain-general advantage due to AP. However, speech-violin accuracy correlations for AP musicians were almost zero at the longer ISI, suggesting less commonality of mechanisms during more extensive processing. Results are discussed in terms of the role of AP in tone language perception.