Training Japanese listeners to identify English vertical bar r vertical bar and vertical bar l vertical bar: Long-term retention of learning in perception and production

Previous work from our laboratories has shown that monolingual Japanese adu lts who were given intensive high-variability perceptual training improved in both perception and production of English /r/-/l/ minimal pairs. In this study, we extended those findings by investigating the long-term retention of learning in both perception and production of this difficult non-native contrast. Results showed that 3 months after completion of the perceptual training procedure, the Japanese trainees maintained their improved levels of performance on the perceptual identification task. Furthermore, perceptu al evaluations by native American English listeners of the Japanese trainee s' pretest, posttest, and 3-month follow-up speech productions showed that the trainees retained their long-term improvements in the general quality, identifiability, and overall intelligibility of their English /r/-/l/ word productions. Taken together, the results provide further support for the ef ficacy of high-variability laboratory speech sound training procedures, and suggest an optimistic outlook for the application of such procedures for a wide range of "special populations."