Nasalance Variability in 3- to 5-Year-Old Children during Production of Speech Stimulus in Three Vowel Contexts

Abstract

Objective: The purpose of this study was to determine whether age and vowel contexts influence test-retest nasalance score variability in typically developing Korean children. Participants: Forty-five 3- to 5-year-old children with normal speech and resonance participated in the study. Methods: All subjects were asked to repeat three 4-syllable speech stimuli in high, low, or mixed vowel contexts twice after the examiner. An immediate test-retest nasalance score was assessed with no headgear change. Test and retest variability in nasalance scores was examined based on the absolute difference in nasalance scores of the first and second repetition for each stimulus. Results: A significant main effect of the vowel context on variability in nasalance scores was found, but the effect of age on nasalance variability was not significant. Mean absolute difference in nasalance scores for the stimuli in the high vowel contexts was significantly greater than for the stimuli in the low and mixed vowel contexts. Conclusions: The results suggested that variability in nasalance scores might not decrease with age and tend to show considerable individual variations. Increased variability in nasalance scores in the high vowel context might be associated with aerodynamic and acoustic characteristics resulting from physiological aspects of the vowel /i/.