Effect of vowel context on test-retest nasalance score variability in children with and without cleft palate

Objective: The purpose of this study was to determine whether test-retest nasalance score variability differs between Korean children with and without cleft palate (CP) and vowel context influences variability in nasalance score. Participants: Thirty-four 3-to-5-year-old children with and without CP participated in the study. Methods: Three 8-syllable speech stimuli devoid of nasal consonants were used for data collection. Each stimulus was loaded with high, low, or mixed vowels, respectively. All participants were asked to repeat the speech stimuli twice after the examiner, and an immediate test-retest nasalance score was assessed with no headgear change. Results: Children with CP exhibited significantly greater absolute difference in nasalance scores than children without CP. Variability in nasalance scores was significantly different for the vowel context, and the high vowel sentence showed a significantly larger difference in nasalance scores than the low vowel sentence. The cumulative frequencies indicated that, for children with CP in the high vowel sentence, only 8 of 17 (47%) repeated nasalance scores were within 5 points. Conclusions: Test-retest nasalance score variability was greater for children with CP than children without CP, and there was greater variability for the high vowel sentence(s) for both groups.