Preprint manuscript, data files, and complete analytic code for: Preston, J.L., McAllister, T., Phillips, E., Tiede, Boyce, S.E., Tiede, M., Kim, J.S., Whalen, D.H. (2019). Treatment for residual rhotic errors with and without ultrasound visual feedback: A single case experimental study. *American Journal of Speech-Language Pathology, 28*(3), 1167-1183. doi: https://doi.org/10.1044/2018_JSLHR-S-17-0441 **Purpose**: To examine how ultrasound visual feedback (UVF) treatment impacts speech sound learning in children with residual speech errors (RSE) affecting /ɹ/. **Method**: Twelve children ages 9-14 received treatment for vocalic /ɹ/ 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 /ɹ/ in untreated words. **Results**: After the first 8 sessions, children who received UVF were judged to produce more accurate vocalic /ɹ/ 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 /ɹ/ errors. Better outcomes were also observed when UVF was provided in the early rather than later stages of learning. However, there remains significant individual variation in response to UVF as well as traditional treatment, and larger group-level studies are needed. ***Funding**: Research reported in this publication was supported by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health under Award Number R01DC013668 (D. Whalen, PI). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.*