MEASURING KNOWLEDGE OF ENGLISH ORTHOTACTICS IN JAPANESE LEARNERS OF ENGLISH: TOWARDS THE ESTABLISHMENT OF A TRAINING SCHEME FOR /l/-/r/ PERCEPTION

Existing regimes on training Japanese learners of English to acquire the nonnative contrast /l/ and /r/ in English focus on having the learners attend to differences in acoustics cues. Such training does show a certain amount of improvement in /l/-/r/ discrimination among Japanese learners, yet the level of achievement is not equivalent to the performance of native speakers. In light of the fact that phonological contrasts are based not only on acoustic information and that other dimensions such as phonotactics also plays a significant role, the current study explores the possibility of setting up a training scheme that supplements Japanese learners of English with an understanding of the probabilistic phonotactics of /l/ and /r/ for better discrimination of the two categories. This training would be meaningful only if it is made clear that Japanese learners of English do not possess such phonotactic knowledge while native English speakers do. As a first step, native speakers of English were tested on whether they are able to make a category decision based solely on probabilistic orthotactic information, to simulate a situation where the category is ambiguous between /l/ and /r/ in terms of acoustic cues but can be clearly defined by phonotactic constraints in English. It was confirmed that native English speakers do have knowledge on orthotactics and were overall successful in making a correct category judgment. However, although it had been predicted that Japanese native speakers lack the orthotactic knowledge of L and R and would fail in the category judgment, the Japanese speakers tested in this study performed just as well as the native speakers of English. However, having orthotactic knowledge only suggests a possibility of having phonotactic sensitivity indirectly, since processing of a written word and speech sound is not the same. Emphasis is often placed on reading and writing in the English classroom in Japan, and many students find processing spoken language more demanding. Besides, English is notorious for its unsystematic writing system and the letter-to-phoneme correspondence is very inconsistent. Further studies that directly measure the phonotactic knowledge of Japanese learners of English are necessary.