Is seeing believing? The role of ultrasound tongue imaging and oral corrective feedback in L2 pronunciation development

This study compares the effects of visual and oral corrective feedback (CF) on L2 pronunciation development. While many studies have investigated the effects of oral CF for various types of L2 learner productions (Li, 2010; Mackey & Goo, 2007), research in visual biofeedback is still developing (Antolik et al., 2019; Gick, et al., 2008). In this study, 21 Japanese learners of English were divided into two groups: an oral CF group and a visual (ultrasound) CF group where participants received either oral or visual feedback on task-essential pronunciations of English /l/ and /r/ after induced communication breakdowns in task-based interactions. Development, determined by accuracy ratings of /l/ and /r/ productions and comprehensibly ratings of phrases from reading passages by naive raters, was examined pre and post participation in task-based interactions. Introspective reports in the form of stimulated recall interviews assessed learners' noticing of visual and oral CF and provided qualitative evaluations of the utility of ultrasound imaging for improving pronunciation. Findings uncovered gains for the group who received biofeedback using ultrasound on a story reading task, but not a word list task, when compared with learners who only received oral CF. The training was positively received by participants with those in the ultrasound group finding use of the ultrasound motivating and useful for their production of /r/ and /l/.