The role of auditory processing in L2 vowel learning: evidence from recasts

Developing adequate second language (L2) speech has increasingly become one of the important goals in today’s globalized world. The current study set out to investigate how the provision of recasts can facilitate English vowels /i/-/ɪ/ learning by Chinese native speakers and how such learning gains resulting from recasts can be tied to individual differences in auditory processing. An experimental group of thirty young adults was engaged in ten treatment sessions of recasts lasting ninety minutes each to notice and practice English vowels /i/-/ɪ/. Their learning gains were tested through a forced-choice identification task, a controlled word-reading task, and a spontaneous picture-narrative task before and after receiving recasts. A control group of the same number of participants was also included to receive comparable sessions without receiving any recasts to check for test-retest effects. Quantitative analysis showed that recasts significantly helped Chinese native speakers facilitate their learning of English vowels /i/-/ɪ/ regardless of time and lexical context. Such learning gains resulting from recasts were significantly correlated with specific constructs of auditory processing. Namely, perceptual acuity was significantly correlated with gains from recasts in identifying L2 vowels, and audio-motor integration with gains from recasts in controlled/spontaneous production of L2 vowels. The findings suggest that recasts can serve as ideal instructional techniques of L2 vowel learning for Chinese native speakers and that the auditory processing profiles of individuals can suggest how they can benefit the most from recasts.