Nasal airflow patterns during the velopharyngeal closing phase in speech in children with and without cleft palate

Objectives: (1) To study the nasal airflow patterns during the velopharynge al closing phase in speech produced by children with and without cleft pala te. (2) To compare the nasal airflow patterns in bilabial, dental, and vela r articulation in these children. Design: Prospective, cross-sectional study of a consecutive series of child ren with cleft palate referred for routine speech evaluation and controls. Setting: Sahlgrenska University Hospital, Goteborg, Sweden. Participants: Seventeen children with cleft lip and palate or cleft palate only and 22 controls aged 7 and 10 years. Method: Nasal airflow was transduced with a pneumotachograph attached to a nose mask and registered together with the acoustic speech signal. Sentence s containing nasal-to-stop combinations in bilabial, dental, and velar arti culatory positions were used. Main Outcomes Measures: The duration from peak to 5% nasal airflow the maxi mum flow declination rate, and the nasal airflow at selected points in time during the transition from nasal-to-stop consonants. Results: in the cleft palate group, duration from peak to 5% nasal airflow was clearly Longer than among the controls (p < .0001). The declination of airflow was slower (p < .006) and the rate of nasal airflow at the release of the stop consonant was, higher (p < .004) in the cleft palate group. Dif ferences between bilabial versus dental and velar articulation were found i n the control group. Conclusion: Studies of the temporal and dynamic characteristics of the nasa l airflow variations during speech appear potentially useful for the assess ment of velopharyngeal function.