Modifying speech to children based on their perceived phonetic accuracy

Purpose: The authors examined the relationship between adults' perception of the accuracy of children's speech and acoustic detail in their subsequent productions to children. Method: Twenty-two adults participated in a task in which they rated the accuracy of 2- and 3-year-old children's word-initial /s/ and /∫/ using a visual analog scale (VAS), then produced a token of the same word as if they were responding to the child whose speech they had just rated. Result: The duration of adults' fricatives varied as a function of their perception of the accuracy of children's speech: Longer fricatives were produced following productions that they rated as inaccurate. This tendency to modify duration in response to perceived inaccurate tokens was mediated by measures of self-reported experience interacting with children. However, speakers did not increase the spectral distinctiveness of their fricatives following the perception of inaccurate tokens. Conclusion: These results suggest that adults modify temporal features of their speech in response to perceiving children's inaccurate productions. These longer fricatives are potentially both enhanced input to children and an error-corrective signal.