The Effect of Vowel Contexts on Voice Onset Time of Mandarin Word-Initial Stops

This study, based on corpus materials, investigates the “voice onset time” (VOT) of Mandarin word-initial stops in isolated syllables according to the effect of vowel contexts produced by native and non-native speakers. 1250 monosyllables of word-initial plosives /p/, /t/, /k/, /p^h/, /t^h/, and /k^h/ were uttered in combination with the vowels /a/, /i/, and /u/ in four tone contexts except /ki/ and /khⁱ/ that are phonetically illegal in Mandarin by 20 participants (10 native Chinese speakers and 10 Urdu learners of Chinese). Results show that for native Chinese speakers, VOTs of aspirated stops followed by the high vowels /i/ and /u/ are significantly longer than those followed by the low vowel /a/, and unaspirated stops followed only by the back high vowel /u/ are significantly longer than those followed by the low vowel /a/. For native Urdu speakers, it can be said that mean VOTs of word-initial stops in Mandarin monosyllables have no significant effect for both aspirated and unaspirated ones in combination with different vowels. Understanding the results of this study will be of assistance to second language learning and teaching.