Age of learning affects the authenticity of voice-onset time (VOT) in stop consonants produced in a second language

TLDR

The study investigates whether Spanish–English bilinguals who learn English early can fully differentiate /t/ VOT, and posits that late learners use different realization rules, yielding longer VOT. Experiment 1 measured VOT in Spanish and English words across Spanish monolinguals, English monolinguals, and bilinguals with early or late L2 acquisition, while Experiment 2 replicated these measurements in alternating Spanish–English utterances. Results show Spanish monolinguals have shorter VOT than English monolinguals; late L2 learners exhibit intermediate VOT, whereas early L2 learners match English monolinguals, indicating that early acquisition allows distinct phonetic categories while late acquisition does not.

Abstract

This study examined whether Spanish–English bilinguals are able to fully differentiate Spanish and English /t/ according to voice-onset time (VOT) if they learn English as a second language (L2) in early childhood. In experiment 1, VOT was measured in Spanish words spoken by Spanish monolinguals, in English words spoken by English monolinguals, and in Spanish and English words spoken by bilinguals who learned English either as young children or as adults. As expected, the Spanish monolinguals produced /t/ with considerably shorter VOT values than the English monolinguals. Also as expected, the late L2 learners produced English /t/ with ‘‘compromise’’ VOT values that were intermediate to the short-lag values observed for Spanish monolinguals and the long-lag values observed for English monolinguals. The early learners’ VOT values for English /t/, on the other hand, did not differ from English monolinguals’ VOT. The same pattern of results was obtained for stops in utterance-medial position and in absolute utterance-initial position. The results of experiment 1 were replicated in experiment 2, where bilingual subjects were required to produce Spanish and English utterances (sentences, phrases, words) in alternation. The results are interpreted to mean that individuals who learn an L2 in early childhood, but not those who learn an L2 later in life, are able to establish phonetic categories for sounds in the L2 that differ acoustically from corresponding sounds in the native language. It is hypothesized that the late L2 learners produced/t/ with slightly longer VOT values in English than Spanish by applying different realization rules to a single phonetic category.