What is the function of immature vocalizing in early learning environments? Previous work on infants in the US indicates that prelinguistic vocalizations elicit caregiver speech which is simplified in its linguistic structure. However, there is substantial cross-cultural variation in the extent to which children’s vocalizations elicit responses from caregivers. In the current study we ask whether children’s vocalizations elicit similar changes in their immediate caregivers’ speech structure across two cultural sites with differing perspectives on how to interact with infants and young children. Here we compare Tseltal Mayan and US caregivers’ verbal responses to their children’s vocalizations. Similar to findings from US dyads, we found that children from the Tseltal community regulate the statistical structure of caregivers’ speech simply by vocalizing. Following the interaction burst hypothesis, where clusters of child-adult contingent response alternations facilitate learning from limited input, we reveal a stable source of information facilitating language learning within ongoing interaction.

What predicts individual differences in children’s acquisition of consonant production across languages? Considerations of children’s development of early speech production have traditionally emphasized inherent physiological constraints of the vocal apparatus that speakers generally have in common (i.e., articulatory complexity). In contrast, we propose a statistical learning account of phonological development, in which phonological regularities of the ambient language guide children’s learning of those regularities in production. Across four languages (English, Spanish, Japanese, and Korean), we utilized recent meta-analytic dataset of age of consonant acquisition spanning 28 studies. High-density measures of children's ambient language environment from over 8,000 transcripts of speech directed to over 1,000 children were used to assess how well the frequency of consonants in child-directed speech predict the age of consonant acquisition. Our results suggest that both frequency and articulatory complexity are related to age of acquisition, with similar results found for English, Spanish, Japanese, and Korean. Consonants heard frequently by children tended to be incorporated into their production repertoires earlier and consonants heard less frequently are incorporated into production repertoires later in development. We discuss future directions that incorporate a statistical learning pathway towards learning to produce the sound patterns of the ambient language.

In auditory statistical learning, children are sensitive to the transitional structure of their language environment. Vari-ability and stability of utterances in the language environment are important properties of statistical learning but are currentlyunderstudied across laboratory and naturalistic research contexts. In this study, we quantify variability and stability in the lan-guage environment of children as measured by amount of information within the temporal structure of caregivers’ utterances. Inthis work we present a new method for understanding information signatures in the temporal structure of parent-child free playcontexts and document information signatures of caregiver utterances at multiple timescales. Our results suggest informationsignatures of parental utterances increase across development (9-24 months), but decrease within individual play sessions (5-6minutes). We speculate that the dynamics of information signatures varies across multiple timescales. Possible implications ofthe observed information signatures inherent in caregivers’ naming of objects to their young children are explored.