The Perception of Cantonese Vowel Length Contrast by Mandarin Speakers

The study investigates the perception of vowel length contrasts in Cantonese by native Mandarin speakers with varying degrees of experience in Cantonese: naïve listeners (no exposure), inexperienced learners (~1 year), and experienced learners (~5 years). While vowel length contrasts do not exist in Mandarin, they are, to some extent, exploited in English, the second language (L2) of all the participants. Using an AXB discrimination task, we investigate how native and L2 phonological knowledge affects the acquisition of vowel length contrasts in a third language (L3). The results revealed that all participant groups could discriminate three contrastive vowel pairs (/aː/-/ɐ/, /ɛː/-/e/, /ɔː/-/o/), but their performance was influenced by the degree of Cantonese exposure, particularly for learners in the early stage of acquisition. In addition to vowel quality differences, durational differences were proposed to explain the perceptual patterns. Furthermore, L2 English perception of the participants was found to modulate the perception of L3 Cantonese vowel length contrasts. Our findings demonstrate the bi-directional interaction between languages acquired at different stages, and provide concrete data to evaluate some speech acquisition models.