Infant-directed speech in English and Spanish: Assessments of monolingual and bilingual caregiver VOT

•Monolinguals and bilinguals exaggerate VOT in IDS in English and Spanish.•Late-L2 bilinguals produce English stops with English- and Spanish-like properties.•L2-proficiency plays a role in bilinguals' realization of English stops.

It has been shown that monolingual caregivers exaggerate acoustic speech cues in infant-directed speech (IDS), but less is known about the characteristics of IDS in late second-language (L2) bilingual caregivers. Furthermore, there is inconsistency in the literature regarding voice onset time (VOT) of stop consonants in IDS. The present study explores VOT of English and Spanish stops in English monolingual and Spanish-dominant bilingual caregivers, in infant- versus adult-directed speech registers. Both monolinguals and bilinguals exaggerate VOT in IDS; however, different patterns are noted across consonant type and language context. Also, bilinguals produced English stops with Spanish-like and English-like properties, depending upon their L2-proficiency. The characteristics of late-L2 Spanish-English bilingual IDS may create a complex phonetic environment for infants, which may in turn affect the perception and later production of stop consonants in dual language-learning infants.