Phonetic analyses of the speech development of babies with cleft palate.

Phonetic transcription was completed of the vocalizations of 23 babies with cleft palate at 9 specified ages from 3 to 36 months of age. Frequency of occurrence was calculated for: (1) consonant place features, (2) consonant manner features, (3) stop types, (4) fricative types, (5) vowel place features, and (6) vowel height features. The data are discussed for the entire population, for those babies with greater palatal tissue for whom palatoplasty was conducted at or prior to 12 months of age and for those babies with lesser tissue for whom palatoplasty was conducted after 12 months of age. Results suggest that (1) neither group used oral place features at the rate produced by babies born with intact velopharyngeal mechanisms, but that (2) the greater tissue group exhibited somewhat higher emergence of oral stop and fricative productions.