Can F3 be Used to Teach Japanese Adults /r / and /l/?

Can native Japanese speakers be successfully taught to differentiate the English sounds /r / as in “rock ” and /l / as in “lock”? Earlier investigations using synthesized stimuli (Strange & Dittman, 1984) showed poor generalization to natural speech, while training on speech of several speakers (e.g., Bradlow et al, 1997) led to long-lasting improvements that generalized but still did not approach native levels. Acoustic measurements of /r / and /l / reveal the primary distinction is the third formant (F3) onset frequency. For /r/, onset is low and rises to the vowel; for /l/, onset is higher and stays relatively flat. Yamada and Tohkura (1990) found that while native American English speakers are sensitive to this cue, native Japanese speakers seem to rely on the second formant (F2). We hypothesized that by limiting training stimuli suc