Real-time visual acoustic feedback in computer-assisted pronunciation training

Abstract

Previous research on visualization of speech segments for pronunciation training suggests that such learning results in improved segmental production (e.g., Katrushina et al., 2015; Olson, 2014; Patten & Edmonds, 2015). However, investigation into real-time formant visualization for L2 vowel production training has been limited to either training a single or a pair of vowels (Carey, 2004; Sakai, 2016) and to examination of improvement on trained items only (Katrushina et al., 2015). This project investigates the effects of real-time formant visualization on production training for eight L2 vowels in trained and untrained environments as well as spontaneous speech. L2 learners (n = 11) participated in nine 30-minute training sessions, during which they used a formant visualization system to practice their vowel production. A control group (n = 8) was involved in audio-only vowel production training. Pre-test, post-test, and delayed post-test design was used, and pronunciation improvement was analyzed acoustically using Mahalanobis distance and mixed-effects modeling. The use of real-time visual acoustic feedback resulted in retained improvement in vowel quality in both trained and untrained items than audio-only training. Spontaneous speech was not improved. The findings suggest that this system could be used as an effective pedagogical tool for L2 learners.