Predicting native English-like performance by native Japanese speakers

This study tested the predictions of the Speech Learning Model (SLM, Flege, 1988) on the case of native Japanese (NJ) speakers' perception and production of English /ɹ/ and /l/. NJ speakers' degree of foreign accent, intelligibility of /ɹ–l/ productions, and ability to perceive natural speech /ɹ–l/ were assessed as a function of length of residency in North America, age of arrival in North America, years of student status in an English environment, and percentage of Japanese usage. Additionally, the extent to which NJ speakers' utilized the F3 onset cue when differentiating /ɹ–l/ in perception and production was assessed, this cue having previously been shown to be the most reliable indicator of category membership. As predicted, longer residencies predicted more native English-like accents, more intelligible productions, and more accurate natural speech identifications; however, no changes were observed in F3 reliance, indicating that though performance improves it does so through reliance on other cues.

► Native Japanese /ɹ–l/ changes with English immersion duration.
► Natural speech /ɹ–l/ perception improves with increased length of residency.
► Intelligibilty of /ɹ–l/ productions improves with increased length of residency.
► There were no predictors of acoustic cue sensitivity in perception or production.