L2 acquisition and L1 attrition of VOTs of voiceless plosives in highly proficient late bilinguals

While much research has examined second language (L2) phonetic acquisition, less research has examined first language (L1) attrition in terms of the voice onset time (VOT) of voiceless stops. The current study examined L2 acquisition and L1 attrition in the VOT of word-initial voiceless stops among late English-Arabic and Arabic-English bilinguals in order to explore the role of phonetic similarity in L2 acquisition and L1 attrition of speech. The study included 60 participants: 15 monolingual Arabic speakers, 15 monolingual English speakers, 15 English-Arabic bilinguals and 15 Arabic-English bilinguals. The bilinguals had been living in their L2 environment for more than 15 years. The participants narrated two cartoons in Arabic and/or three in English. The monolingual groups' results revealed clear cross-language differences in the VOT of voiceless plosives between the two languages. Phonetic similarity affected L2 acquisition in that those L2 sounds that were close in phonetic space to L1 sounds (i.e. /t/ and /k/) were more difficult to acquire than those that were dissimilar to L1 sounds (i.e. /p/). However, L1 attrition showed an asymmetric pattern, occurring only in the English-Arabic bilinguals' productions of the English /k/. We suggest that markedness might contribute to explaining this asymmetry.