Growth in the accuracy of preschool children’s /r/ production: Evidence from a Longitudinal Study

The acquisition of American English /r/ is of particular theoretical and clinical interest because it is typologically rare among the world’s languages, because it is one of the latest-acquired sounds by typically developing children, and because it is one of the sounds that is most likely produced in error by children with residual speech sound disorders. In this study, we examined the accuracy productions of /r/ and its most frequent substitute, /w/, by preschool children (n = 120) at two time-points: when they were between 3;3 (years;months) and 4;4 years old and again when they were 4;4 to 5;4 years. Accuracy was determined both by trained phonetic transcriber. Moreover, the accuracy of productions from the first time-point was rated by groups of naive listeners using a perceptual rating experiment similar to that described by Schellinger et al. (2016). Considerable variation in /r/ production was found at both time-points, and there was sizeable variation in the extent to which production improved fr...