Intraword variability in typical speech development.

Purpose: Intraword variability (sometimes called token-to-token variability) has been associated with certain types of speech disorder. It has also been documented in typical speech development. The purpose of this study was to investigate intraword variability in typically developing 2- and 3-year-olds to determine expected rates and patterns of variability in typical speech development.

Method: Participants were 33 children aged 2;6 (years;months) to 3;11 with typical speech development. Three productions of 25 target words were elicited, and an overall variability score was calculated. Response type and the effect of word length were investigated.

Results: Variability rates decreased with age; however, the oldest children (ages 3;6-3;11) continued to display considerable variability. The most common response type was variable with no hits (i.e., variable production with none matching the target form) for all age groups, and variability was greatest for longer words.

Conclusions: Variability is prevalent in the speech of typically developing 2- and 3-year-olds and was observed even in the oldest children. Future work is needed to determine at what age this type of phonemic variability is no longer prevalent in typical speech development. Clinicians should use caution in interpreting the presence of intraword variability as indicative of specific subtypes of speech disorder.