Ability in perceiving nonnative contrasts: Performance on natural and synthetic speech stimuli

The perception of the distinction between /r/ and /l/ by native speakers of American English and of Japanese was studied using natural and synthetic s peech. The American subjects were all nearly perfect at recognizing the nat ural speech sounds, whereas there was substantial variation among the Japan ese subjects in their accuracy of recognizing /r/ and /l/ except in syllabl e-final position. A legit model, which additively combined the acoustic inf ormation conveyed by F1-transition duration and by F3-onset frequency provi ded a good fit to the perception of synthetic /r/ and /l/ by the American s ubjects. There was substantial variation among the Japanese subjects in whe ther the F1 and F3 cues had a significant effect on their classifications o f the synthetic speech. This variation was related to variation in accuracy of recognizing natural /r/ and /l/, such that greater use of both the FI c ue and the F3 cue in classifying the synthetic speech sounds was positively related to accuracy in recognizing the natural sounds. However, multiple r egression showed that use of the F1 cue did not account for significant var iance in natural speech performance beyond that accounted for by the F3 cue , indicating that the F3 rue is more important than the F1 cue for Japanese speakers learning English. The relation between performance on natural and synthetic speech also provides external validation of the legit model by s howing that it predicts performance outside of the domain of data to which it was fit.