Convergence effects in Spanish-English bilingual rhythm

This study examines the rhythmic properties of highly proficient Spanish-English bilinguals. Ten Spanish-English bilinguals who live in the United States read aloud sentences in Spanish (their L1) and English (their L2), and ten Spanish and ten English monolingual control speakers read aloud sentences in their respective native languages. We performed an acoustic analysis of vocalic and consonantal durations and applied four timing metrics with the intent of measuring rhythmic variability across groups. We used two Pairwise Variability Index (PVI) metrics (nPVI-V and rPVI-C) and two variation coefficient (Varco) metrics (VarcoV and VarcoC). Results show that the Spanish and English monolingual control groups pattern as expected for syllableand stresstimed languages, respectively. The bilingual speakers show separate statistical distributions in their L1 and L2 rhythms, implying that they produce separate rhythms in their two languages. Further analysis revealed that the bilingual speakers were consistently English-like in English (their L2) but were not consistently Spanish-like in Spanish (their L1). These data support the notion that extensive exposure to an L2 facilitates development toward native-like command of L2 rhythmic patterns, and that this can further lead to L2-to-L1 convergence effects.