LAUSR

Dynamic L2 effects on L1 phonetics appear in experienced and novice second language learners, raising the question of what linguistic and cognitive factors determine their occurrence, degree, and direction (assimilatory versus dissimilatory). Unlike Chang (2012), our longitudinal data from voiceless stops in early L1 English:L2 Japanese learners show primarily dissimilatory increase in English VOTs, an effect found most strongly early in their first semester. Assimilatory L1 drift toward the lower VOTs of L2 Japanese may be disfavored because a decrease in English voiceless stop VOT could threaten the L1 contrast between long and short lag stops. Furthermore, dissimilatory VOT increase on voiceless stops allows English speakers to distinguish phonetically similar L1 and L2 voiceless stops (e.g., Flege and Eefting 1987). These two principles predict that our voiced stop data could show increased L1 prevoicing (an assimilatory effect that would not endanger the English voicing contrast), while also displayi...