Training Japanese listeners to identify English /r/ and /l/: long-term retention of learning in perception and production

Abstract

Previous work from our laboratories has shown that monolingual Japanese adults 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 of the perceptual identification task. Furthermore, perceptual evaluations by native American English listeners of the Japanese trainees' 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 efficacy 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."

Figure 1

Percent correct perceptual identification performance for trained (left) and control (right) subjects at pretest, posttest, and 3-month follow-up for the subjects who participated in all three test phases. The error bars represent one standard error of the mean.

Figure 2

Proportion of trials in which the pretest tokens were preferred versus the proportion of trials in which the posttest tokens (circles) or 3-month follow-up tokens (squares) were preferred for both trained and control subjects.