Pitch-shift responses as an online monitoring mechanism during level tone production

This paper investigates whether pitch-shift responses can be modulated as a function of level tone height in Taiwanese Southern Min (TSM). Twenty-six native TSM speakers were recruited and asked to produce three TSM words that differed in tone on the first syllable but had the same mid-level tone on the second syllable (hence, HM, MM, and LM). The pitch-shift stimuli appeared at 100 ms after vocalization onset and lasted for 200 ms. The magnitudes of the pitch-shift stimuli were ±250 cents for HM, +250/-150 cents for MM, and ±150 cents for LM, in order to overlap the shifted pitch with another lexical tone. The results show that larger pitch-shift peak amplitudes were elicited when the H level tone of the HM word was downshifted 250 cents to the M level and when the L level tone of the LM word was upshifted 150 cents to the M level tone. However, no significant direction effect was found for the MM word. The M level tone might be perceived non-categorically by native TSM speakers. Overall, the findings suggest that the magnitudes of pitch-shift responses may have to do with the degree of categorical perception.