Voice onset time of alveolar stop /t/ and realization of unaspirated affricates associated with Mandarin-speaking children with repaired cleft palate.

PURPOSE: To examine perceptually the realization of unaspirated affricates and voice onset time (VOT) features of /t/ in Mandarin-speaking children with repaired cleft palate, and to explore the difficulties associated with unaspirated affricate production from the perspective of the VOT of /t/.

METHOD: Twenty-three children with repaired cleft palate and 22 age-matched typical native Mandarin speakers were recruited. Speakers with cleft palate were allocated into two groups based on expert perceptual judgment of nasality: one group with perceived normal resonance (PNR) (n = 14, average age = 9.3 years), and another group with perceived hypernasal resonance (PHR) (n = 9, average age = 10.3 years).

INTERVENTION: Stimuli were collected through a series of picture naming tasks, targeting the production of initial consonants /t/ and three unaspirated Mandarin affricates /ts, tʂ, tɕ/. The productions of each affricate were evaluated by two experienced speech therapists. The VOT of /t/ was measured using PRAAT speech analysis software.

RESULT: The majority of unaspirated affricates were omitted and/or weakly realized by the group of PHR speakers, but not for the PNR group. A significantly smaller mean VOT value associated with /t/ was identified for the PHR group, as compared to the PNR group. A group difference for VOT value was not found between the PNR group and the typical control group.

CONCLUSION: The voicing features of /t/ and omitted/weak realization of unaspirated affricates identified in the PHR group indicated that the deviant production of unaspirated affricates in the cleft palate group could be associated with the voicing characteristics of the alveolar stop /t/, and this merits further investigation.