“…The quantity and quality of speech input from adult caregivers predicts children's lexical processing speed (Weisleder & Fernald, 2013), syntactic complexity (Huttenlocher, Vasilyeva, Cymerman, & Levine, 2002), expressive and receptive vocabulary sizes (Hoff 2003;Mahr and Edwards 2017), babbling complexity (Ferjan Ramírez, Lytle, Fish, and Kuhl 2019;Ramírez-Esparza, García-Sierra, and Kuhl 2014), and speech perception (Cristia, 2011;Garcia-Sierra, Ramírez-Esparza, & Kuhl, 2016;Liu et al, 2003). Infants and young children are capable of tracking statistical patterns from their input, such as phoneme or word co-occurrences, and reflecting those patterns during phoneme discrimination and word segmentation tasks (Maye, Werker, & Gerken, 2002;Pelucchi, Hay, & Saffran, 2009), consonant production (Edwards & Beckman, 2008;Zamuner, 2009), and early, pre-lexical vocalizations (de Boysson-Bardies, Vihman, & de Boysson-Bardies, 1991;Ha, Johnson, Oller, & Yoo, 2021).…”