The intelligibility of the English vowel /ʌ/ produced by native speakers of Japanese and its relations to the acoustic characteristics

This paper examined the intelligibility of the English mid-low central vowel / / produced by 20 native Japanese speakers (JE / /), and the acoustic characteristics of JE / / according to the different levels of intelligibility. Five native English speakers evaluated the intelligibility of JE / / in the word “but.” F1 and F2 frequencies and the duration of JE / / were measured and compared with those of / / spoken by native English speakers and the Japanese vowel /a/. It was found that JE / / with lower intelligibility was more often misheard for the low front vowel / / by the American listeners and tended to have a longer duration and higher F1 and F2 frequencies. L1 transfer occurred in the pronunciation of / / by the Japanese speakers, which resulted in the differences in the perception of JE / / by the native English speakers.