Remediating residual rhotic errors with traditional and ultrasound-enhanced treatment: A single-case experimental study

Abstract

Purpose: The aim of the study was to examine how ultrasound visual feedback (UVF) treatment impacts speech sound learning in children with residual speech errors affecting /r{turned}/. Method: Twelve children, ages 9-14 years, received treatment for vocalic /r{turned}/ errors in a multiple-baseline across-subjects design comparing 8 sessions of UVF treatment and 8 sessions of traditional (no-biofeedback) treatment. All participants were exposed to both treatment conditions, with order counterbalanced across participants. To monitor progress, naïve listeners rated the accuracy of vocalic /r{turned}/ in untreated words. Results: After the first 8 sessions, children who received UVF were judged to produce more accurate vocalic /r{turned}/ than those who received traditional treatment. After the second 8 sessions, within-participant comparisons revealed individual variation in treatment response. However, group-level comparisons revealed greater accuracy in children whose treatment order was UVF followed by traditional treatment versus children who received the reverse treatment order. Conclusion: On average, 8 sessions of UVF were more effective than 8 sessions of traditional treatment for remediating vocalic /r{turned}/ errors. Better outcomes were also observed when UVF was provided in the early rather than later stages of learning. However, there remains a significant individual variation in response to UVF and traditional treatment, and larger group-level studies are needed.