Have four-year-olds mastered vowel reduction in English? An acoustic analysis of bilingual and monolingual child storytelling

Recent studies show that late Spanish-English bilingual adults tend to under-reduce or over-reduce English vowels, with hardly any reduction in their Spanish vowels. We examined whether children acquiring Australian English and Spanish simultaneously show similar vowel reduction patterns. Bilingual four-year-olds’ vowel acoustics (spectral and temporal) produced during story comprehension and retelling tasks were measured following previous methods used on childdirected speech. Unlike sequential bilingual adults, simultaneous bilingual four-year-olds mostly resembled monolingual peers in their English vowel reduction and acoustics. Findings are explained using the Second Language Linguistic Perception (L2LP) model, which uses input and language control to explain bilingual performance. Index Terms: English vowel reduction, bilingual Spanish- English preschoolers, bilingual vowel production.