English vowel spaces produced by Japanese speakers: the smaller point vowels' and the greater schwas'.

This study investigated how Japanese-speaking learners of English pronounce the three point vowels /i/, /u/, and /a/ appearing in the first and second monosyllabic words of English noun phrases, and the schwa /ə/ appearing in English disyllabic words. First and second formant (F1 and F2) values were measured for four Japanese speakers and two American English speakers. The hypothesis that the area encompassed by the point vowels in the F1-F2 vowel space tends to be smaller for the Japanese speakers than for the English speakers was verified. The hypothesis that the area formed by the three schwas in chicke_n, spoonfu_l, and Tarza_n is greater for the Japanese speakers than for the English speakers and its related hypothesis were largely upheld. Implications for further research are briefly discussed.