Improvement of speech perception following articulatory-target based production training for second language acquisition.

Direct training of articulatory movements can be an effective and efficient tool for second language learning. We have previously developed an articulatory target-based training method using electromagnetic articulography for second language pronunciation. In this training, an estimate of a participant's target midsagittal tongue posture is presented on a display together with the real-time position of their tongue, and used as feedback for adjusting their tongue position to the target position. We showed that Japanese participants improved their pronunciation of American English vowel /æ/, which is not in the Japanese vowel inventory, toward more native-like pronunciation following the training. The current study investigates whether this articulatory target-based training approach, which demonstrably improves production, enhances perception of the corresponding speech sounds. Seven Japanese male speakers participated, performing an ABX perceptual test before and after training, contrasting minimal pairs: /æ/-/ɑ/, /æ/-/ʌ/, and /ɑ/-/ʌ/ within consonant-vowel-consonant words. Results showed that, in spite of the large range of observed variability in individual participants' responses to the articulatory target-based training, overall, there were significant improvements in both production and perception of /æ/. Our findings suggest that motor processing related to speech production contributes to the improvement of speech perception for the second language acquisition, and shows that articulatory target-based training approaches can be useful for enhancing both production and perception in second language acquisition.