The effects of tone categories on the perception of Mandarin vowels

In order to explore the effects of tone categories on the perception of Mandarin vowels, the present study investigated the perceptual performance of vowel continua, which contained three Mandarin vowels /a, ɤ, u/ under four different tone conditions (i.e. high-level, mid-rising, falling-rising, and high-falling tones). The results showed that there was a shift in the categorical boundaries of /a/-/ɤ/ among the four different tone conditions. More specifically, participants generally tended to label the stimuli less as /a/ under the high-falling tone compared with the other three tone conditions. Moreover, the maximum identification rate of /ɤ/ was much lower under the falling-rising tone in contrast with other tone conditions. These findings suggest that vowel perceptions may be strongly influenced by the pitch properties of different tone categories.