Words in context: Compensation for phonological assimilation in monolingual and bilingual toddlers

Most words spoken to infants are produced in larger units, such as clauses, phrases, and sentences. As such, language learners must recognize words amidst the words that surround them. However, the phonetic forms of words change based on surrounding context. Here, we investigate the effects of a common source of phonetic change—phonological assimilation—on word recognition in English monolingual and English-Mandarin bilingual infants from Singapore. Using a preferential looking paradigm, 24-month-old monolingual English and bilingual English-Mandarin toddlers were presented with three different forms of familiar English words embedded in phrases: correct productions (e.g. ‘Look at the pen, dear’), assimilated forms (e.g. ‘Look at the pem, baby’), and mispronunciations (e.g. ‘Look at the pem, dear’). Although participants preferentially fixated visual targets upon hearing them labeled, there were no effects or interactions of language background and trial type on target fixation. However, higher naming effects were associated with increased English exposure in bilingual infants. The results suggest that monolingual and bilingual infants respond similarly to phonetic alternations arising from nasal place assimilation at 24 months.