The Role of ASR Training in EFL Pronunciation Improvement: An In-depth Look at the Impact of Treatment Length and Guided Practice on Specific Pronunciation Points

Abstract

Several studies have suggested that pronunciation practice through automatic speech recognition (ASR) tools can help learners improve second language pronunciation. However, the treatment length varies from study to study, making it unclear whether a longer treatment at shorter intervals or a more intensive treatment for longer intervals will have a greater impact. Furthermore, since most studies include both teacher instruction and ASR-based practice, it is unclear how much impact is due to the feedback and guided practice of the ASR tools and how much is due to teacher instruction. This study seeks to discover if ASR-based practice has a measurable impact on student performance discernable from teacher instruction, which pronunciation points are most impacted by such practice, and whether treatment length affects learning outcomes. We found that L1 Japanese English as foreign language (EFL) learners were more likely to improve on vowel-related pronunciation and that while treatment length over a single semester did not have a large impact on learning outcomes, the feedback from an ASR-based practice tool caused students to focus on their pronunciation and adjust it, often for the better. Therefore, we conclude that ASR-based pronunciation tools are meaningful in a wide variety of Japanese EFL contexts and recommend their usage.