Transfer of L1 tone knowledge to L2 vowel quantity contrasts as a secondary cue: The case of Cantonese learners of Japanese

Distinguishing vowel quantities in Japanese is problematic for Cantonese-speaking learners. Vowel length is lexically contrastive in Japanese but not in Cantonese. Apart from duration, fundamental frequency (F0) patterns are secondary cues to vowel length distinction. As tone is lexically contrastive in Cantonese (particularly rising vs. high level), learners would likely be able to transfer this phonological knowledge to help themselves acquire vowel length contrast in Japanese. A perception experiment was conducted in which learners listened to Japanese disyllabic words. The first syllable of which was lengthened according to the within-word vowel duration ratio in eight steps. A level or dynamic (rising or falling) F0 pattern was then imposed on the first vowel. Similar to other L2 learners, Cantonese-speaking learners did not perceive the long vs. short contrast categorically, but gradiently. While both dynamic F0 patterns signal a long vowel, they only exploited the rising pattern to recognise a long vowel. Our study suggests that learners have assimilated the falling contour to high level, both of which belong to the same tonal category in Cantonese. The theoretical implications of these results are discussed.