Perceptual evaluation of speech and velopharyngeal function in children with and without cleft palate and the relationship to nasal airflow patterns

Objectives: The aim was to study the relationship between perceptual evaluation of speech variables related to velopharyngeal function and the pattern of nasal airflow during the velopharyngeal closing phase in speech in children with and without cleft palate. Participants: Fourteen children with cleft lip and palate or cleft palate only and 15 controls aged 7 and 10 years. All were native Swedish speakers. Method: Three experienced listeners performed a blinded perceptual speech evaluation. Nasal airflow was transduced with a pneumotachograph attached to a nasal mask. The duration from peak to 5% nasal airflow, maximum flow declination rate, and nasal airflow at selected points in time during the transition from nasal to stop consonants in bilabial and velar articulatory positions in sentences were estimated. The analysis was focused on the perceptual ratings of "velopharyngeal function" and "hypernasality." Results: A strong association was found between ratings of "velopharyngeal function" and "hypernasality" and the pattern of nasal airflow during the bilabial nasal-to-stop combination /mp/. Both the sensitivity and specificity were 1.00 for the bilabial temporal airflow measure in relation to ratings of "velopharyngeal function." The nasal airflow rate during /p/ in /mp/ had a sensitivity of 1.00 and specificity of 0.92 to 0.96 in relation to ratings of "hypernasality." Conclusion: Assessment of the nasal airflow dynamics during the velopharyngeal closing phase in speech presents quantitative, objective data that appear to distinguish between perceptually normal and deviant velopharyngeal function with high sensitivity and specificity.