The purpose of this study was to investigate the use of electropalatography (EPG) and ultrasound in the remediation of vowels in adolescents with hearing impairment. Three adolescents with severe hearing impairment participated in a 6-week vowel remediation programme using electropalatography (EPG) and dynamic two-dimensional ultrasound as adjuncts to speech therapy. Pre- and post-therapy speech productions were evaluated in terms of vowel formant values, EPG tongue-palate contact patterns and phonetic transcription. Notable changes were observed for all vowels across speakers, with most changes in the direction of the adult English targets. Transcription, acoustic and EPG tongue-palate contact results did not necessarily converge across vowels or speakers. Visual feedback as provided by EPG and ultrasound can be facilitative in promoting vowel development in adolescents with hearing impairment. Further research is required to evaluate the stability of changes, the relative impact of ultrasound and EPG and the relationship between phonetic transcriptions, tongue-palate contact and acoustic information about vowels.