Laryngeal airway resistance in children with cleft palate and adequate velopharyngeal function.

Laryngeal airway resistance during vowel production was determined for 10 children without cleft palate and 14 children with cleft palate and adequate velopharyngeal function. The children with cleft palate were further grouped according to either complete or incomplete velopharyngeal closure. All children performed a syllable repetition task with nostrils occluded at self-determined effort and a targeted effort typical of adult speech. Results indicated that all children exhibited significantly greater laryngeal resistance at self-determined effort. No significant differences occurred among the groups of children at either effort level. Some children with incomplete velopharyngeal closure, however, tended to exhibit relatively increased laryngeal resistance at the targeted effort level when their nostrils were unoccluded. Implications for a regulation-control model of speech production and clinical assessment are discussed.