The functional speech sound disorder, American English /r/ articulation errors, presents a unique and confounding clinical challenge as therapy resistant residual errors persist into adolescence and adulthood in many cases. Finding paucity of empirical research for /r/ treatment, evidence-based practice (EBP) exploration in motor-related disorders informed clinical practice and research directions. This study investigated the efficacy of manual mimicry (a kinesthetic, gestural, and visual cue) in treating intractable /r/ errors in a young adult using a single subject ABAB design. Perceptual accuracy judgments of three types of listeners (experts, graduate clinician, and naïve listeners) indicated a positive treatment effect of manual mimicry cueing on vocalic /r/ sound productions. Electropalatograpy (EPG) outcome measures showed limited ability to accurately reflect perceptual changes quantitatively. These findings from an exploratory study provide initial evidence that perceptual saliency of /r/ productions may be potentially remediated using a kinesthetic, gestural, and visual cue during treatment
