A developmental process of English vowel acquisition by Korean adult L2 learners

Abstract

The purpose of this study is to address Korean adult L2 learners’ developmental English vowel acquisition process. The present study demonstrated how adult L2 learners turn their initial L2 proficiency into more advanced state, and how new L2 sound system relates with existing L1 sound system. The present study hypothesized that L2 learners’ phonetic category is subject to change followed by three stages of L2 vowel acquisition process: Stage 1 (Initial L2 proficiency), Stage 2 (Intermediate L2 proficiency), and Stage 3 (Advanced L2 proficiency). Secondly, this study hypothesized that L2 learners’ identity /attitudes/motivation may have an influence on their L2 perception and production.

To investigate Korean L2 learners’ English vowel learning process, this study carried out longitudinal experiments with 8 Korean adult L2 learners for 6 months. The experiments were conducted on a monthly basis and the procedure was controlled in a laboratory setting to examine any possible changes of L2 ability during L2 learning process. English tense/lax vowel contrasts (/i/-/I/ and /u/-/(n/a)/) and Korean rounded/unrounded vowels (/(n/a)(i)/ and /(n/a)(u)/) were used for the experiments. 360 tokens of English vowels (60 words × 2 vowel pairs × 3 speakers) were used for each perception test and a total of 2,160 stimuli (360 tokens × 6 times) were generated for perception experiments. Korean participants produced 360 tokens of English vowels (60 words × 2 tense/lax vowel pairs × 3 sets) and 160 tokens of Korean vowels (40 words × 2 rounded/unrounded vowels × 2 sets) in each production test. A total of 2,160 English tokens (360 tokens × 6 times) and 960 Korean tokens (160 words × 6 times) were generated for production experiments. Two different phonetic environments were provided; a case of cross-language similarity environment and an emergence of a new sound category.

The results demonstrated that Korean L2 learners’ English vowel productions have changed to a more native-like English vowel production through their L2 learning process. Thus, in the final experiment, Korean L2 learners’ English vowel production showed almost an exact similarity to native speakers’ vowel production. The present study investigated the relationship between adult L2 learners’ identity/motivation/attitudes and their L2 vowel perception and production. The result indicated that higher identity/attitudes/motivation may result in advanced L2 vowel perception and production. L2 learners’ L2 proficiency developed gradually. Hence the L2 learners’ L2 learning is able to be considered to be following the sequential development pattern accompanied by the process of L2 learning.