Tongue-palate contact patterns for Japanese speakers with and without cleft lip and palate

Abstract

Abstract Purpose: Visual feedback therapy, using electropalatography (EPG), has been used to remedy residual articulation errors associated with cleft palate. The tongue-palate contact patterns of typical speakers without cleft palate are usually used as a model. However, it is questionable whether these model patterns are adequate for clients with repaired cleft palate, as their dento-palatal morphology is different from non-cleft speakers. The objective of this study was to investigate the differences in tongue-palate contact patterns between typical speakers with and without cleft palate. Method: EPG data were recorded for alveolar consonants in 15 participants with repaired unilateral cleft lip and palate (UCLP) whose speech was perceptually assessed as typical Japanese. The cumulative templates for each consonant were generated from the maximum contact frame; quantitative analyses (centre of gravity [CoG], variability index) were performed. Fifteen typical Japanese speakers without cleft served as a control group. Result: EPG patterns for each consonant were generally similar between groups. The CoG value of the UCLP group was significantly lower only for /s/. The average variability index was higher for every consonant but the comparisons did not reach significance. Conclusion: The typical tongue-palate contact patterns can be used as a model of visual feedback therapy.