Relationships between integrated oral-nasal differential pressure and velopharyngeal closure.

Oral-nasal differential pressures are derived measures that incorporate both active (e.g., articulatory) and passive (e.g., nasal structure) components. This study was designed to examine integrated oral-nasal differential pressures in speakers with different levels of velopharyngeal closure. Integrated oral-nasal differential pressure data were obtained from 20 noncleft adults with normal speech and 166 speakers with repaired palatal clefts. Velopharyngeal competency for the cleft subjects, as determined by aerodynamic assessment, ranged from adequate to grossly incompetent. Results of the data analysis indicate that integrated pressures are not maintained at a consistent level across all groups. This lack of consistency across all degrees of velopharyngeal opening may reflect the flexibility, as well as structural limitations, of a speech pressure regulating system.