Effects of speech style on the perceptual assimilation of American English vowels by Japanese speakers.

Abstract

Of specific interest in this study was the extent to which speech style (citation form versus sentence form) affected perceptual assimilation of AE vowels by Japanese listeners. Four adult male speakers produced 11 AE vowels in /hVba/ bisyllables in both citation form (lists) and in the sentence ‘‘I hear the /hVb/ on the tape.’’ Response categories, designated in Katakana symbols, included five short vowels, five long vowels, and eight vowel combinations (e.g., ou, ei, ja:). Twenty‐four Japanese listeners selected the response category which was most similar to the /hV/ syllable they heard and rated its ‘‘goodness of fit.’’ Results indicated that, in general, AE vowels were assimilated to the Japanese vowel category closest in articulatory vowel space. However, intrinsic duration information was utilized much more consistently when the syllables were embedded in a carrier sentence. That is, intrinsically long (or diphthongized) AE vowels were assimilated to long‐vowel or two‐vowel response categories more often in the sentence condition. Acoustical analysis indicated that some, but not all, of the variation in assimilation patterns could be explained by F1/F2 variation. Implications for Japanese L2 learners of English are discussed. [Work supported by NIDCD.]