Auditory Acuity and Response to Altered Auditory Feedback in Children with and without Rhotic Distortions.

Introduction Children with residual speech sound disorder (RSSD) exhibit speech production patterns that differ from their dialect community and persist beyond the typical developmental window. Differences in sensory acuity or sensory feedback response may contribute to these persisting deviations. Methods To assess this, the present study evaluated response to altered auditory feedback in 46 children aged 9-15 who represented two groups: children with RSSD (5 female, 15 male) and children without RSSD (13 female, 13 male). Participants heard their speech in near real-time with the first formant frequency shifted upwards by 30%. We also administered an explicit behavioral measure of auditory-perceptual acuity involving discrimination of the phonetic contrast featured in the altered auditory feedback task. Results One sample t-tests demonstrated statistically reliable adaptation effects in altered-F1/hold and after-effect phases for both groups of children. The groups did not differ in auditory-perceptual acuity. A linear mixed-effects model revealed no differences between the two groups in response during altered feedback; however, children with RSSD exhibited reduced adaptation in the after-effect phase, indicating weaker modification of feedforward commands. Performance on the auditory discrimination measure was significantly related to the magnitude of response to altered auditory feedback for children without RSSD, but not for children with RSSD. Conclusion These findings suggest that altered auditory feedback can inform our understanding of the ability of children with speech sound disorders to adjust their motor plans for speech production.