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 Iri-ill 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, 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 1r1-11/ 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."Over the past decade, several important advances have been made toward establishing effective laboratory training procedures for modifying the identification of difficult non-native phonetic categories (for recent reviews, see

Perceptual learning for speech: Is there a return to normal?

“…For example, improved intelligibility has been found after sufficient exposure to synthetic speech (Greenspan, Nusbaum, & Pisoni, 1988;Maye, Aslin, & Tanenhaus, 2003), compressed speech (Dupoux & Green, 1997;Mehler et al, 1993), and nonnative accented speech (Bradlow & Bent, 2003;Bradlow, Pisoni, Akehane-Yamada, & Tohkura, 1997;Bradlow, Akehane-Yamada, Pisoni, & Tohkura, 1999). Clearly, listeners learn something about the speech they are exposed to and use what they learn to improve their perception of similar speech.…”

Perceptual learning for speech

“…Production accuracy was judged by a group of naive American listeners. In addition to perceptual improvements, Bradlow et al (1997;Bradlow et al, 1999) found moderate but significant improvements in production. Like the perceptual gains, those in production were intact after a three-month period with no additional training.…”

“…This difference reflects an inherent tension that must be resolved in a learning system: Specifically tuning the representations/ processes for the training input may optimize performance on the stimuli prevailing in the environment, but there are also advantages to being able to generalize the learning to new sources. Bradlow, Pisoni, Akahane-Yamada, and Tohkura (1997;Bradlow, Akahane-Yamada, Pisoni, & Tohkura, 1999) tested whether the gains made with perceptual training also enhance the ability of Japanese speakers to produce the English / /-/ / distinction. Bradlow et al (1997;Bradlow et al, 1999) used training procedures similar to those of Lively et al (1994), and measured both perceptual and production accuracy before and after the training regime.…”

“…Bradlow, Pisoni, Akahane-Yamada, and Tohkura (1997;Bradlow, Akahane-Yamada, Pisoni, & Tohkura, 1999) tested whether the gains made with perceptual training also enhance the ability of Japanese speakers to produce the English / /-/ / distinction. Bradlow et al (1997;Bradlow et al, 1999) used training procedures similar to those of Lively et al (1994), and measured both perceptual and production accuracy before and after the training regime. Production accuracy was judged by a group of naive American listeners.…”

From sound to meaning

“…Attempts to train motivated learners on difficult sound contrasts-for example, efforts to teach native speakers of Japanese to hear differences between /l/ and /r/ sounds-usually show modest gains after many hours of training. 10 Some people learning a new language reach native-like performance, but most fall short of that goal, even after a lifetime's immersion. 11 Many factors make it hard to learn the sounds of a new language.…”