The long-term retention of phonetic categories by Japanese immersion graduates

Abstract

English-speaking children in a Japanese immersion program, in which many content subjects are taught in Japanese, were reported to be successful in establishing phonetic categories for single and geminate stops in Japanese, although their categories deviated from those of Japanese monolinguals. However, it is unknown to what extent those children can retain their phonetic categories after they exit the program. Ten participants who had attended a Japanese immersion program in the United States from kindergarten or grade 1 to grade 5 and who were taking a university-level intermediate or advanced Japanese course at the time of data collection were recorded producing Japanese words including both singletons and geminates. Mean closure duration values were obtained, and the ratio of geminates to singletons for the immersion graduates was compared with that of English learners of Japanese having the same proficiency level in a regular Japanese program. The results show that the immersion graduates, who had been exposed to a substantial amount of Japanese at an early age, still retained the phonetic categories and could contrast singletons with geminates in Japanese, although their closure duration tended to be longer than the norm of monolingual Japanese speakers.