Abstract:

Mounting evidence has shown that native language (L1) phonetic representations can be affected by extensive second language (L2) learning. In this study the nature and time course of this phonetic drift in L1 are examined in a longitudinal investigation of 20 L1 English speakers’ first 5 weeks of learning Korean as L2. Acoustic analyses of these learners’ L1 and L2 speech production over time show that learning L2 stops affects the production of L1 stops (in terms of VOT and∕or f0 onset) in as little as 1 week, with the L1 sounds approximating the L2 sounds to which they are most phonetically similar. English voiced stops do not change significantly in VOT over time, since they are already similar to Korean fortis stops in this respect; however, they rise in f0 onset in approximation to the elevated f0 onset typical of Korean fortis stops. Meanwhile, English voiceless stops become longer in VOT and higher in f0 onset in approximation to the Korean aspirated stops. These results indicate that L1 phonological categories are affected by L2 learning on a very short timescale, suggesting that the L1‐L2 equivalence classification that gives rise to this phonetic drift may be rather low‐level in nature.