Vowel Space in Children with Repaired Cleft Lip and Palate Compared to Normal Peers

Cleft lip and palate is an innate malformation in a person’s palate and upper lip which causes disorder in vocal tract. The present article aims to study vowel space in children with repaired cleft lip and palate and compare it to their normal peers with disability and voice as factors. So, Persian vowels were studied in CVC framed words. These words were produced by 12 participants, 6 children with repaired cleft lip and palate and 6 normal children, and were recorded using PRAAT software. Then, first and second formants were measured and after that the data was analyzed statistically. The results revealed that the effect of disability on first formant of vowels [æ, e, u], and second formant of vowels [æ, ɒ, o, u] is significantly different. The results also showed that the effect of voice on first formant of vowels [æ, e] is significantly different. Moreover, it was proved that the vowel space in children with cleft lip and palate is in lower place and near to the lips comparing to the vowel space in children with normal vocal tracts and vowel space in voiced context is different from voiceless context.