What does more time buy you? Another look at the effects of long-term residence on production accuracy of English /inverted r/ and /l/ by Japanese speakers.

This study tested the issue of whether extended length of residence (LOR) in adulthood can provide sufficient input to overcome age effects. The study replicates Flege, Takagi, and Mann (1995), which found that 10 out of 12 Japanese learners of English with extensive residence (12 years or more) produced liquids as accurately as native speakers of English (NS). Further, for both accuracy and native-like accentedness, the Japanese with extensive residence performed statistically better as a group than inexperienced Japanese (less than 3 years of residence). Results with a new sample of Japanese learners in this study found no statistical difference between the Japanese groups with extended versus short LOR although both reported equal levels of daily input in English. Additionally, both groups received statistically lower scores than NS. Moreover, LOR affected the two groups differently: The accuracy and native-like accentedness of words and sentences by Japanese with extensive residence declined with LOR (and chronological age when age of arrival was partialled out), while for Japanese with short residence accent improved with increased LOR (but not age). This study is the first to document a decline in second language production ability with LOR and age in older second language learners. However, this finding deserves to be addressed with further research, as the study was not designed to investigate this question and thus not all relevant factors, such as motivation or attitude, were controlled for. The results from the short-residence learners indicate that the initial one to two years of immersion may be the most important for improving phonological ability.