Oral Diadochokinetic Performance on Perceptual and Acoustic Measures for Typically Developing Cantonese-Speaking Preschool Children.

Purpose: This study investigated native Cantonese-speaking preschool children's diadochokinetic performance, including rate, accuracy, and regularity. The second aim of this study was to examine whether language-specific patterns exist by comparing diadochokinetic rates with the average DKK rate for native English speakers.

Method: Sixty-four typically developing preschool children who were native Cantonese speakers participated. The diadochokinetic task administered to the children involved repetitions of monosyllabic, disyllabic, and trisyllabic words and nonsense words. The maximum performance of the children was compared by diadochokinetic rate (number of syllables per second), accuracy (percentage of matched production), and regularity (pairwise variability indexes, known as PVIs).

Results: Monosyllabic units were produced faster, more accurately, and more regularly than multisyllabic units. Word repetition showed higher accuracy and generally lower regularity than nonsense words but similar rates. Older children were faster and more regular (higher raw PVI of initial consonants) than younger children, but younger children performed as accurately as them. When compared with data from English speakers, the diadochokinetic rates of Cantonese children were generally lower.

Conclusions: Developmental progression was evident in terms of rate and regularity. The distinctive accuracy and regularity patterns between word and nonsense word repetition suggest a clinical value for both stimulus types. Language typology plays a role in diadochokinetic rate, supporting the use of language-specific reference data in practice. The typical diadochokinetic profile obtained in this study could serve as a clinical reference for speech motor assessments.