Stephen Lambacher
The study focuses on the problems that Japanese learners have in distinguishing between the voiceless fricatives [th] and [s] through an acoustical analysis of these sounds as produced by native and Japanese speakers. Japanese learners have difficulty particularly in both listening to and producing the [th] which to native speakers of English sounds like a variant form of [s]. It is not easy for many Japanese to distinguish between [th] and [s] in listening to normal conversation, unless exceptional enunciation is given to [th]. One possible reason for this inability to discriminate between [th] and [s] is that Japanese has fewer fricatives than English. Also, no corresponding [th] fricative exists within the Japanese sound system. Acoustically, the Japanese [th] and [s] resemble one another much more so than the native speaker [th] and [s]. Not only is the acoustical energy of the [th] spoken by Japanese significantly greater than that spoken by native speakers, but results revealed even a greater difference in energy between the [s] spoken by Japanese and that of a native English speaker. By comparing the spectral differences of Japanese and native speaker recorded production of [th] and [s], this paper posits that these production differences may at least partly explain the significant acoustic discrimination difficulties of these sounds experienced by Japanese speakers of English.