The current study provides evidence supporting the view that recent L2 speech perception models can be extended to the suprasegmental level. The results indicate a significant and systematic in flounce of language experience on tone assimilation,
revealing that perceptual sensitivity to the distinctions between tone categories depends on previous exposure to a tone system.Allophonic tone variation is found to be tied to tone assimilation at the phonological level. However, as this phenomenon does not exist in Thai, in the current study it was possible to examine tone assimilation only in relation to the Mandarin tone system. In future work, researchers should consider investigating tone assimilation in language pairs employing different tone systems that both carry allophonic tone contrasts, such as Mandarin and Cantonese (Yu, 2007;Zee, 1999). Additionally,phonological tone assimilation may also be explored by replacing L1 tone categories with L2 tone categories on a number of real words in L1 (Best & Tyler, 2007). Given only a difference in tone, if the replacement (e.g., M-HL replaced by T-ML for a Mandarin word) does not affect word meanings, such finding may suggest that the two tone categories share the same phonological function.Future research may also investigate assimilation of other prosodic features, such as Japanese pitch accent and English word stress.Like lexical tones, these features are realized at the word level with distinctive phonetic properties (Wu, Tu, & Wang, 2012); thus it is worth comparing the effects of phonetic and phonological factors in the assimilation of different prosodic patterns. Moreover, since suprasegmental assimilation is linked with listeners' L2 experience,
further work may incorporate L2 experience at different stages,allowing for a longitudinal observation of the establishment of an L2 phonological system or the formation of L2 phonological categories.