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

ABSTRACT

OBJECTIVES: (1) To study the nasal airflow patterns during the velopharyngeal closing phase in speech produced by children with and without cleft palate. (2) To compare the nasal airflow patterns in bilabial, dental, and velar articulation in these children. DESIGN: Prospective, cross-sectional study of a consecutive series of children with cleft palate referred for routine speech evaluation and controls. SETTING: Sahlgrenska University Hospital, Göteborg, 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. Sentences containing nasal-to-stop combinations in bilabial, dental, and velar articulatory positions were used. MAIN OUTCOMES MEASURES: The duration from peak to 5% nasal airflow, the maximum 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. Differences between bilabial versus dental and velar articulation were found in the control group. CONCLUSION: Studies of the temporal and dynamic characteristics of the nasal airflow variations during speech appear potentially useful for the assessment of velopharyngeal function.