Accuracy of diadochokinetic performance in 5–10-year-old children

Background: Diadochokinetic (DDK) rate is often used as the primary measure to evaluate articulatory speed in children. However, examining the accuracy of children’s DDK productions can provide critical additional insights (e.g. Williams & Stackhouse, 2000), especially for interpreting atypical performance. Despite this, few studies have systematically analysed accuracy, with most excluding incorrect productions from rate calculations.
This study investigated the accuracy and error patterns of monosyllabic (/pɛ/, /tɛ/, /kɛ/) and trisyllabic (/pɛtɛkɛ/) productions in 77 English-speaking children aged 5;3–10;3 years.
Method: Children’s DDK productions were recorded using an app, and subsequently labelled and analysed for accuracy in terms of frequency and types of errors. Errors were categorised into changes in voicing, place and manner of articulation, and addition of sounds following Yaruss & Logan (2002).
Results: Preliminary analysis of monosyllabic productions revealed that 33.8% of children produced at least one error during /p/ production, with fewer children producing errors in /t/ (29.9%) and /k/ (23.4%). Across the group, frequency of errors varied by phoneme, with /p/ having the highest average error rate (13.8%, range = 0-100%), followed by /t/ (9.2%, range = 0-100%) and /k/ (3.5%, range = 0-44.9%). Errors were present across all ages, regardless of phoneme. Voicing errors (e.g., /p/ → [b]) were the most common, followed by combined place and manner changes (e.g., /p/ → [ʋ]). Subsequent analyses will examine the link to DDK rate and the potential impact of reported medical issues on performance.
Conclusion: Findings show that children up to 10 years can show errors in DDK productions, demonstrating the relevance of including accuracy analyses alongside DDK rate to fully capture articulatory abilities in primary school aged children. A comprehensive understanding of accuracy and error patterns will be beneficial for interpreting atypical performance, enhancing the clinical utility of DDK tasks as a diagnostic measure.