Abrupt Laryngeal Engagement during Stop Plosive-Vowel Transitions in Children with Repaired Cleft Palate and Adequate Velopharyngeal Closure: Aerodynamic and Sound Pressure Level Evidence

Abstract

Objective To determine whether children with repaired cleft palate and adequate velopharyngeal closure exhibit abrupt laryngeal engagement during stop plosive-vowel transitions as compared with children without cleft palate. Design A prospective group design was used with convenience sampling of patients at a university craniofacial center. Participants Participants were 25 children (15 boys, 10 girls) with repaired cleft palate (mean age = 10.9 years, standard deviation = 1.5 years) and 20 children (10 boys, 10 girls) without cleft palate (mean age = 10.8 years, standard deviation = 1.8 years). All children with cleft palate had adequate velopharyngeal closure as determined by aerodynamic testing. Main Outcome Measures (1) Peak oral airflow was determined during the release of /t/ in the word “two” during a counting task. (2) An index of laryngeal engagement defined as the ratio of the maximum oral airflow declination to peak oral airflow was calculated during the release of /t/. (3) Sound pressure level was determined during the vowel of the word “two.” Results Children with cleft palate exhibited significantly more negative laryngeal engagement ratios (i.e., more abrupt adduction) ( P = .002) and greater sound pressure level ( P = .049) than controls. There was a significant negative relationship between laryngeal engagement and sound pressure level for all children ( r = -.428, P = .003). Conclusions Children with repaired cleft palate and adequate velopharyngeal function appear to use a strategy of abrupt laryngeal adduction during stop plosive-vowel transitions. This strategy—perhaps learned even prior to palate surgery—may help to achieve either adequate sound pressure level and/or velopharyngeal closure.