The perception of English vowel contrasts by Chinese EFL learners and native English speakers

Previous studies have shown that some English vowel contrasts remain difficult for English learners to perceive. This study investigated three potential factors affecting vowel perception: cross-language vowel systems, spectral distance, and language proficiency, for the discrimination and identification of English /ɪ/-/ε/, /ε/-/æ/, /ʊ/-/ʌ/, and /ʌ/-/ɒ/ contrasts in four groups of listeners: L1-Chinese with beginner level, low proficiency, and high proficiency in English, and L1-native English speakers. Eight 10step vowel continua were used in identification and AXB discrimination tasks. Results reveal that the disparity in the correctness in the discrimination task for L1-Chinese is higher than that for L1-native English speakers. No overall positive correlation is found between spectral distance and vowel discrimination, though positive correlation can be found in either front or back vowel contrasts when discussed separately. As language proficiency is enhanced, front vowels are perceived more categorically, while such a tendency is not shown in back vowel contrasts.