English Vowel Perception in Spanish-English Bilingual Preschoolers: Multiple-Talker Input Is Only Beneficial for Children With High Language Exposure Levels.

This study shows that bilingual children can show monolingual-like perception patterns for some sounds while displaying nontarget perception for others. This is the first study to demonstrate that language exposure mediates the role of input diversity on speech sound development, suggesting that varied input can be more or less beneficial for speech sound development based on the learner's language learning stage.