Shifting Perceptual Weights in L2 Vowel Identification after Training

Abstract

Difficulties with second-language vowel perception may be related to the significant challenges in using acoustic-phonetic cues. This study investigated the effects of perception training with duration-equalized vowels on native Chinese listeners' English vowel perception and their use of acoustic-phonetic cues. Seventeen native Chinese listeners were perceptually trained with duration-equalized English vowels, and another 17 native Chinese listeners watched English videos as a control group. Both groups were tested with English vowel identification and vowel formant discrimination before training, immediately after training, and three months later. The results showed that the training effect was greater for the vowel training group than for the control group, while both groups improved their English vowel identification and vowel formant discrimination after training. Moreover, duration-equalized vowel perception training significantly reduced listeners' reliance on duration cues and improved their use of spectral cues in identifying English vowels, but video-watching did not help. The results suggest that duration-equalized English vowel perception training may improve non-native listeners' English vowel perception by changing their perceptual weights of acoustic-phonetic cues.

Fig 1

Vowel identification scores in correct-response percentage of normal duration, equalized duration of trained vowels in the pre-training test, post-training test, and retention test of the vowel training group (Fig 1a: Upper left) and of the control group (Fig 1b: Upper right). Vowel formant discrimination scores of /ʌ/ in the pre-training test, post-training test, and retention test of the vowel training group (Fig 1c: Bottom left) and of the control group (Fig 1d: Bottom right). Error bars represent the standard deviations of the means. * Symbol represents significant differences: p < 0.05; and ** represents p < 0.01.

Fig 2. Cohen's d of the duration effect for both the vowel training group and the control group collapsed over the test time (pre-training, post-training, and retention tests).

Fig 3. The correlation between the scores of the vowel identification (VID) of normal or equalized duration and the thresholds of vowel formant discrimination (VFD) of /ʌ/ in the pre-training, post-training, and retention tests of both the vowel training group and the control group.