Phonetic equivalence in the acquisition of /l/ by Spanish-English bilingual children

Spanish [l] is characterized as clear, and is associated with a high second formant (F2) frequency and a large difference between F2 and the first formant (F1) frequencies. In contrast, English [l] is darker (with a lower F2 and a relatively smaller F2-F1 difference) and also exhibits contextual variation due to an allophonic velarization rule that further darkens [l] postvocalically. We aimed to determine if Spanish-English bilingual children evidence these differences productively, in a manner comparable to that of monolinguals, or if they produce an [l] that is intermediate to that of Spanish and English monolinguals. We acoustically analyzed [l] productions of seven Spanish-English bilingual, seven Spanish monolingual, and seven English monolingual children. Results showed that the bilinguals had similar prevocalic F2 and F2-F1 values for [l] in both languages, comparable to those of Spanish monolinguals, but significantly higher than those of English monolinguals. The bilinguals also produced English (but not Spanish) [l] with significantly lower postvocalic F2 and F2-F1 values. We assume that the bilinguals have a merged phonetic category for prevocalic [l] but not postvocalic [l], and further, that they maintain separate grammars, allowing the allophonic velarization rule to apply in English but not Spanish.