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The Korean Association for the Study of English Language and Linguistics
[ Article ]
Korea Journal of English Language and Linguistics - Vol. 25, No. 0, pp.1084-1101
ISSN: 1598-1398 (Print) 2586-7474 (Online)
Print publication date 31 Jan 2025
Received 30 Jun 2025 Revised 23 Jul 2025 Accepted 05 Aug 2025
DOI: https://doi.org/10.15738/kjell.25..202508.1084

The Role of Perceptual and Acoustic Similarity in Learners’ Perception of L2 Vowels

Shinsook Lee ; Hyunah Baek
(First and corresponding author) Professor, Department of English Language Education, Korea University 145 Anam-ro, Seongbuk-gu Seoul, Korea leesseng@korea.ac.kr
(Co-author) Assistant professor, Department of English Language and Literature Ajou University 206 World cup-ro, Yeongtong-gu Suwon-si, Gyeonggi-do, Korea hyunahbaek@ajou.ac.kr


© 2025 KASELL All rights reserved
This is an open-access article distributed under the terms of the Creative Commons License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study investigates the role of L1-Korean-L2-English vowel similarity and acoustic distance in L1-Korean speakers’ perception of L2-English vowels, given that few studies have examined the joint effects on learners’ L2 vowel perception of L1-L2 sound similarity/dissimilarity and the acoustic distance of L2 vowel production from native speaker reference. Thirty-three Korean learners of English produced and identified 12 English vowels (e.g., bet, but, boat) and mapped the same English vowels onto close Korean vowels. Acoustic distances of the learners’ produced vowels from native English speakers’ norms were calculated as Euclidean distance in the F1/F2 space. The learners’ vowel identification accuracy was assessed and L1-L2 perceptual vowel similarity/dissimilarity was calculated based on the learners’ L2-to-L1 mapping patterns. Results of a linear mixed-effects regression model showed a significant main effect of vowel type (i.e., similar, somewhat similar, dissimilar), indicating that the perception accuracy was significantly higher for L1-similar L2 vowels compared to L1-somewhat similar and L1-dissimilar L2 vowels. The main effect of acoustic distance was also significant, with greater distance associated with lower perception accuracy for L1-similar L2 vowels. However, accuracy rates were varied within each vowel type as the identification accuracies of some L1-somewhat similar or L1-dissimilar L2 vowels tended to be high when they bear salient perceptual cues like vowel duration or r-coloring. These results are only partly in line with the propositions of the Speech Learning Model (SLM/SLM-revised, Flege 1995, Flege and Bohn 2021) concerning the relative difficulty and easiness of the acquisition of L1-similar L2 vowels versus L1-dissimilar L2 vowels, indicating that different L2 vowels develop at different rates.

Keywords:

L2 vowel perception, Korean EFL learners, L1-L2 perceptual similarity, acoustic distance, vowel variations

Acknowledgments

This research was supported by the College of Education, Korea University Grant in 2025. An earlier version of the paper was presented in the 11th International Symposium on the Acquisition of Second Language Speech, New Sounds 2025 (April 22-25), Toronto, Canada.

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