School-aged children's production of /s/ and /r/ consonant clusters

Objective: To describe the acquisition of /s/ and /r/ word-initial consonant clusters across 2 elicitation modalities. Patients and Methods: Seventy-four typically developing children aged 5-12 years produced 2- and 3-element /s/ and /r/ consonant clusters in word-initial position. Stimuli were presented pictorially and as written words in separate trials. Results: Overall, 94.5% of the consonant clusters were produced correctly. Two-element /r/ clusters were 94.0% correct, 2-element /s/ clusters were 96.8% correct, and 3-element clusters were 92.0% correct. The age of acquisition was typically younger than established by previous researchers. The characteristic non-adult production of /s/ consonant clusters was the substitution of /s/ with interdental or lateral phonemes, and of /r/ consonant clusters the substitution of /r/ with [w]. The last consonant clusters to be mastered were: /θr/ (thr), /str/, /spr/ and /skr/. There were no significant differences in error rates across the modalities; although younger children required significantly more prompting when naming written words. Conclusion: Primary-school-aged children characteristically produced /s/ and /r/ consonant clusters correctly. The accuracy of production was not influ- enced by the elicitation modality. Elicitation using pictures compared with written words was more efficient for 5- to 8-year-olds. Both elicitation modes were equally efficient for 9- to 12-year-olds.