Speech segment durations produced by five and six year old speakers with and without cleft palates

Speech segment durations are indicators of the ability to coordinate speech gestures. Development of such temporal aspects of production in the presence of velopharyngeal insufficiency has not been investigated. The present study used spectrograms to measure segment durations in utterances produced by 5 and 6 year old children with and without congenital cleft palates. Subjects had varying degrees of hypernasality and overall intelligibility. Five consonant-vowel-consonant nonsense syllables were formed using /p/, /t/, /k/, /t integral of/, and /s/. The carrier phrases included a single word context, a sentence containing nonnasal sounds, and a sentence with nasals. Experimental group segments were significantly longer than normal in the single word and nasal sentence contexts. Both the syllable and total sentence durations were prolonged. The stop gap of the plosive and affricate consonants was the most deviant individual acoustic segment. Subjects with hypernasality and decreased intelligibility had voice onset times which were significantly longer than those produced by subjects with less disordered speech.