What Do North American Babies Hear? A large-scale cross-corpus analysis.


A range of demographic variables influences how much speech young children hear. However, because studies have used vastly different sampling methods, quantitative comparison of interlocking demographic effects has been nearly impossible, across or within studies. We harnessed a unique collection of existing naturalistic, day-long recordings from 61 homes across four North American cities to examine language input as a function of age, gender, and maternal education. We analyzed adult speech heard by 3- to 20-month-olds who wore audio recorders for an entire day. We annotated speaker gender and speech register (child-directed or adult-directed) for 10,861 utterances from female and male adults in these recordings. Examining age, gender, and maternal education collectively in this ecologically valid dataset, we find several key results. First, the speaker gender imbalance in the input is striking: children heard 2-3× more speech from females than males. Second, children in higher-maternal education homes heard more child-directed speech than those in lower-maternal education homes. Finally, our analyses revealed a previously unreported effect: the proportion of child-directed speech in the input increases with age, due to a decrease in adult-directed speech with age. This large-scale analysis is an important step forward in collectively examining demographic variables that influence early development, made possible by pooled, comparable, day-long recordings of children's language environments. The audio recordings, annotations, and annotation software are readily available for reuse and reanalysis by other researchers.





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Publication Info

Bergelson, Elika, Marisa Casillas, Melanie Soderstrom, Amanda Seidl, Anne S Warlaumont and Andrei Amatuni (2019). What Do North American Babies Hear? A large-scale cross-corpus analysis. Developmental science, 22(1). p. e12724. 10.1111/desc.12724 Retrieved from https://hdl.handle.net/10161/19713.

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Elika Bergelson

Associate Research Professor of Psychology and Neuroscience

Dr. Bergelson's lab has moved to Harvard Psychology; she retains an unremunerated research appointment at Duke through mid-2024 for logistical reasons. She formerly accepted PhD applicants through the Developmental and Cog/CogNeuro areas of P&N and the CNAP program.

In my research, I try to understand the interplay of processes during language acquisition.
In particular, I am interested in how word learning relates to other aspects of learning language (e.g. speech sound acquisition, grammar/morphology learning), and social/cognitive development more broadly (e.g. joint attention processes) in the first few years of life.

I pursue these questions using three main approaches: in-lab measures of early comprehension and production (eye-tracking, looking-time, and in EEG studies in collaboration with the Woldorff lab), and at-home measures of infants' linguistic and social environment (as in the SEEDLingS project).

More recently the lab is branching out to look at a wider range of human populations and at infants who are blind or deaf/heard of hearing.

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