Postdoctoral Fellowship: SPRF: Linking Overheard Speech with Early Language Development

This award was provided as part of NSF's Social, Behavioral and Economic Sciences Postdoctoral Research Fellowships (SPRF) and Linguistics programs. The goal of the SPRF program is to prepare promising, early career doctoral-level scientists for scientific careers in academia, industry or private sector, and government. SPRF awards involve two years of training under the sponsorship of established scientists and encourage Postdoctoral Fellows to perform independent research. NSF seeks to promote the participation of scientists from all segments of the scientific community, including those from underrepresented groups, in its research programs and activities; the postdoctoral period is considered to be an important level of professional development in attaining this goal. Each Postdoctoral Fellow must address important scientific questions that advance their respective disciplinary fields. Under the sponsorship of Dr. Elika Bergelson at Harvard University, this postdoctoral fellowship award supports an early career scientist investigating the role of overheard speech in children's language development. Children’s language and academic success is closely tied to their early language experience. In the U.S., there is a significant “achievement gap” between children from low and high socioeconomic backgrounds, which is often attributed to differences in early language input. Efforts to narrow this gap have focused on encouraging parents to direct more speech to their children. At the same time, recent evidence suggests that this gap is far smaller (and sometime non-existent) when all language input in children’s environment is considered, i.e. both speech directed to a given child and speech to others that they overhear. And yet, little is known about the potential contributions of overheard speech to language learning. Studying the potential role of overheard speech on language learning will advance understanding of what kinds of language input help children become proficient language users. The proposed work has important implications for educational policies and interventions concerning the lifelong success of young children. The proposed work seeks to address two central questions: 1) what are the properties of child-directed and overheard speech and 2) how might speech to different addressees facilitate language development? Using both corpus-based (observational) and lab-based (experimental) approaches, this proposal seeks to thoroughly characterize everyday overheard and child-directed speech and to probe how speech to different addressees may support language learning. This research will use an existing longitudinal corpus, which includes home recordings and language assessment scores, to quantify the linguistic properties of overheard speech and test the relationship between overheard speech and children’s concurrent and later language knowledge. The research will also compare children’s abilities to associate new words and objects from speech directed to others, by probing how intrinsic and extrinsic factors influence children’s ability to leverage input intended for others. This combined approach will provide a nuanced and thorough characterization of overheard speech in real-life settings and uncover how children may learn from it. The results of this work will move theory forward in the field of child language development by considering input that is often ignored by research despite its prevalence in children’s language environments. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.