抄録
The present study describes the acoustic and phonetic characteristics of Japanese (L1) and English (L2) vowels produced by Japanese ESL learners, and examines the learning models in L2 pronunciation. Eleven native speakers of Japanese took part in the experiments, and the measurements were made for F1 and F2 formants of the vowels in both L1 and L2, and the examination was made to characterize the features by male and female groups to reduce speakers' variations. The results of the analysis indicate that the vowel space in L1 and L2 differs in male and female groups in the acquisition of English vowels, and the learners tend to use L1 sounds whose acoustic qualities are close to L2 ones, i.e., Japanese female learners tend to use their own vowel regions to produce American English (AE) vowels which are similar to L1 sounds. From these observations, it can be said that they seem to apply perceptual assimilation model in acquiring L2 vowels.
