The purpose of the study was to ex10amine voice onset time (VOT) and its variability in children with childhood apraxia of speech (CAS) compared to typically developing children. Twelve children with CAS aged 9-12 years old and 20 children who were age-matched participated in the study. This study measured VOT and variabilities of VOT during the production of /p' a/, /t' a/, /k' a/. For variability measures of VOT, each participant was asked to repeat speech tasks three times and the average

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... ue of the rates and its standard deviation were obtained The verification of the hypotheses was tested by using T-test of the significance level of 0.05.The results showed that the variability of VOT in CAS group was more significantly higher than control group. But VOT of /p' a/, /t' a/, /k' a/ between the experimental group and the control group was not significantly different. The results suggested that variability of VOT might be more distinctive speech feature to children with CAS than the VOT.