THE UNIVERSITY OF BRITISH COLUMBIA FACULTY OF GRADUATE STUDIES

This study examines the effectiveness of using visual feedback from ultrasound in remediation of persistent ITI errors. Ultrasound provides the learner and the clinician with a dynamic sagittal or coronal image of the tongue during speech production. The participants in this study were two adolescent boys ages 12 and 14 who had not yet learned to produce an on-target North American IT I in any context. Both participants had received at least one year of traditional IT I therapy without improvement. Therapy was provided over 13 one-hour sessions using visual feed back from ultrasound. Initially, the ITI was broken down into individual motor targets (tip, body, root); these components were then practiced in combination to produce Irl in isolation, then in syllables, words, and phrases. Post-treatment improvements were analyzed through transcription, acoustic analysis, and tongue shape measurement. Both participants' ITI productions were rated as having more tokens of on-target Irl post-treatment. Acoustic results supported these findings with a lowering of the third formant post-treatment. Tongue shape measures indicated that the participants' tongue shapes were more similar to the modeled tongue shape post-treatment. It was concluded that visual feedback from ultrasound is beneficial in remediation of persistent ITI errors. T A B L E O F C O N T E N T S Abstract ii Table of