Abstract This study explores whether L2-learning environment (i.e., ESL English as a second language vs. EFL English as a foreign language) and vowel type (i.e., L1-similar L2 vowels vs. L1-dissimilar L2 vowels) have an impact on L2 vowel acquisition with reference to the perception-production relationship. L1-Korean learners of English in the U.S. (ESL learners) and Korea (EFL learners) performed English vowel production, English vowel identification, and English-to-Korean vowel mapping tasks using bVt words (e.g., bit, but, bought ). The learners’ English vowel productions were assessed for intelligibility, their vowel identification accuracy was calculated, and their perceptual mapping patterns were used to measure L1-L2 vowel similarity. The results show that the ESL learners outperformed the EFL learners in both perception and production, indicating an effect of L2-learning environment on L2 vowel acquisition. However, both groups showed a significant correlation between perception and production. As for vowel type, the results indicate a significant correlation between perception and production for both L1-similar and L1-dissimilar L2 vowels for the ESL learners but with variations in accuracy rates among L1-dissimilar L2 vowels. For the EFL learners, a significant correlation was found between the two modalities only for L1-similar L2 vowels, while variations in accuracy rates were observed for both vowel types. The results suggest that close counterparts in the L1 may even lead to more successful L2 vowel acquisition relative to L2 vowels without such L1 analogues, especially for ESL learners. The results further suggest that the acquisition of different L2 vowels follows different trajectories, which is ascribed partly to the formation of L2 vowel categories.
Lee et al. (2026) studied this question.