Greater L2 phonetic accommodation does not predict greater L1 phonetic drift in early bilinguals

We explored individual differences in second language (L2) phonetic accommodation and their connection to individual differences in first language (L1) phonetic drift, focusing on changes in Voice Onset Time (VOT) production in 50 early L2 speakers of Indian English in India with L1 Hindi or Telugu. Participants completed four tasks: baseline L1 production, baseline L2 production, L2 accommodation (involving shadowing of American English), and post-accommodation L1 production. Focusing on the bilabial stops /p, b/, we expected accommodation to American English to lead to L2 VOT lengthening and, in turn, to L1 VOT lengthening at the group level. Furthermore, we hypothesized that, at the individual level, greater L2 accommodation would correspond with greater L1 drift. Results showed no significant accommodation for L2 /b/, but significant VOT lengthening for L2 /p/ in both L1 groups. At the group level, no significant L1 drift was observed for /p/ or /b/. However, there was substantial individual variation in both groups. Crucially, speakers who exhibited more VOT lengthening in L2 did not necessarily show more in L1 (r = −0.0.98, p = 0.49). These findings provide counterevidence against a link between individual-level L2 accommodation and L1 drift, suggesting that phonetic malleability may be an individual-difference dimension that is language-specific.