An Investigation into the Use of Ultrasound Tongue Imaging (UTI) as a Biofeedback Tool for Improving the Speech Production of Non-Native Sounds in Second Language Learners

Abstract

Ultrasound Tongue Imaging (UTI) has been used to successfully treat a variety of articulation errors in speech disorders. More recently, however, UTI has been applied to second language acquisition research. This study has been developed as a follow-up to an earlier pilot study (Gick, 2008) with the goal of investigating the pedagogic use of UTI in second language acquisition. UTI will be used as a biofeedback tool to try to improve the pronunciation of the non-native English phonemes /ɹ/ and /l/ in Japanese-English speakers. The study will look at the effectiveness of UTI in improving the perceived accuracy and intelligibility of L2 articulation, in contrast to a control intervention using a speech visualisation mobile application. Finally, the study will investigate whether or not there is a cumulative effect when participants receive intervention using both the speech visualisation mobile application and UTI back to back. Aims- for the participants to accurately produce the non-native target sounds /ɹ/ and /l/ in isolation and at word-level and then be able to generalise these to connected speech; for listeners to perceive connected speech featuring target sounds as more accurate and intelligible. Hypothesis- target sounds will be produced and generalised and perceived accuracy and intelligibility will increase after UTI intervention more significantly than with the control group using a speech visualisation mobile application. Those who receive both interventions sequentially will demonstrate the greatest improvement. Method- Participants: Six English-speaking Japanese females (preferably young adults aged 20-30). Recordings, before and after, of target sounds /ɹ/ and /l/ in isolation, single words and sentences. Ultrasound images, before and after, of target sounds. Listener ratings of accuracy and intelligibility of target sounds in connected speech, before and after. Treatment: six 20-30 minutes sessions (weekly) using ultrasound as a biofeedback tool to teach participants tongue placement/articulation of target sounds /ɹ/ and /l/. Design: single participant design/changing criterion design. The design will include 3 phases: baseline, intervention and follow-up (this will include a long-term follow-up). This design allows participants to act as their own control, however, the group will additionally be divided into two groups to provide a further control. 3 participants will initially receive an intervention involving only a mobile application with the hypothesis that this will not result in any marked improvement. They will subsequently receive the UTI intervention. Comparison of final results with those of the other group will establish or rule out any cumulative effect of both interventions versus solely the UTI intervention.