Acoustics of speech, articulatory compensation, and dental overjet in Cantonese

Studies relating dental anomalies to misarticulations have noted that potential correlations appear to be obscured by articulatory compensation. Accommodation of tongue or mandible positions can help even individuals with severe malocclusion approximate perceptually typical speech [Johnson and Sandy, Angle Orthod. 69, 306-310 (1999)]. However, associations between malocclusion and articulation could surface if examined with acoustic analysis. The present study investigates the acoustic correlates of Cantonese speech as it relates to degree of overjet (horizontal overlap of upper and lower incisors). Production data was collected from native Cantonese-speaking adults, targeting the vowels /i, u, a/, and fricatives /f, s, ts, tsh/, previously found to be vulnerable phonemes in Cantonese speakers with dentofacial abnormalities [Whitehill et al., J Med Speech Lang Pathol. 9, 177-190 (2001)]. Measures of dental overjet and language background were included as well. Preliminary results from trained listeners sh...