Speech segment duration measurements in adult speakers with repaired cleft palate and hypernasality

Consonant closure duration, vowel duration preceding word-final stop consonants, and total VCVC utterance duration were measured in order to investigate if normal durations in these variables were exhibited in subjects with cleft palate and hypernasality. The data revealed no significant differences among three adult subject groups (noncleft, repaired cleft with mild hypernasality, and repaired cleft with severe hypernasality) on any of the duration measurements investigated, suggesting that speech timing for these features were not significantly altered by the presence of the nasal air leak. Speakers in the two hypernasal groups, however, showed smaller differences between vowel durations in voiced and voiceless stop environments than did speakers without cleft palate. There were significant differences among groups in durational cues between vowel types and between voicing features of stop consonants, both of which were in agreement with previous research.