The Effect of consonantal Context and Acoustic Characteristics on the Discrimination Between the English vowel /intersect/ and /square/ by Japanese Learners

摘要

This paper investigated how Japanese learners of English discriminated the American English vowel /intersect/ from /square/ in /CVt/ monosyllables with 23 different initial consonants, and how the differing discrimination was related to the acoustic characteristics of the English vowels compared with those of Japanese vwels /i/ and /e/ in disyllables with a final syllable of /to/. The resutls showed that the overall error rate of /intersect/was significantly higher than that of /square/. This difference between the two vowels in discrimination could be accountedfor by the acoustically closer relations of /intersect/ to the Japanese vowel /e/. It was found, however, that the discrimination of hte two English vowels varied across the consonantal contexts. The error rate was significantly higher when the initial consonant was /t square/, /#lambda#/ or /j/ for /intersect/, and when it was /r/ for /square/. An acosutical analysis indicated that the greater decrease of the ratio of the F2 frequency to the F1 frequency of /intersect/ through the vowel, rather than the acoustical closeness of /intersect/ to the Japense /e/, tneded to be more closely related with the poorer discrimination of this vowel in the particular consonantal contexts.