Previous studies investigating the acquisition of L2 stops have found a positive effect of L2 experience, but few have focused on voiced stops, particularly on prevoicing. This study investigates the acquisition of /b/ and /g/ by two populations, English learners of Spanish and Spanish learners of English. Three groups varying in amount of L2 experience (mainly length of residence, but also L2 use and L2 instruction) were investigated for each L1 population. Participants completed a carrier sentence reading task in their L1 and L2. Results showed that amount of L2 experience had a positive effect on L2 stop production, as the least experienced groups were outperformed by the experienced ones. No clear effect of L2 experience was observed on the L1, as learners did not differ from monolingual controls, but some differences between learner groups emerged. Moreover, overall, L2 learners were able to produce L1 and L2 stops differently, which indicates that their L1 and L2 categories were not merged. Still, the L1-English L2-Spanish speakers produced L2 stops more accurately than the L1-Spanish L2-English groups, suggesting that learning to rely on an existing L1 cue may be easier than learning to use a cue associated with a different L1 category
