Project Summary Children with cochlear implants are at risk of speech and language delays, performing worse than children with normal hearing on virtually every measure of speech, language, and literacy. Children with typical hearing have stronger speech-language outcomes when they hear more language in the home. But children with cochlear implants spend the first months and years of life with little to no auditory input. It remains unclear how the home language environment predicts their speech outcomes. The proposed experiments will evaluate how differences in the everyday language experiences of children with cochlear implants predict their speech-language development. This research will produce evidence that can guide clinicians and pediatricians in recommending at-home practices that promote healthy speech-language development in children with cochlear implants. To accomplish these goals, the team will 1) measure how production practice in children with cochlear implants predicts their spoken language maturity. The team will do this by constructing a large-scale, naturalistic audio corpus to evaluate differences in the quantity of speech that children with and without cochlear implants experience in the home (Experiment 1). It has been suggested that the home language environments of children with hearing loss differ from those of children with normal hearing, but little work has rigorously tested this for preschool children with cochlear implants. In piloting, the research team found that children with cochlear implants heard less speech from adult speakers than their normal-hearing peers, but they did not speak less than the children with normal hearing. Experiment 2 will examine whether the early language environments of children with cochlear implants predict speech production outcomes four months later, a relationship that the research team has documented for children with normal hearing. Next, the team will 2) determine how the quantity of everyday vocalizations and adult input predicts speech discrimination skills in children with cochlear implants. The team will do this by conducting in-lab looking-while-listening eye movement experiments to evaluate discrimination difficulty of different phonemic contrasts (Experiment 3). Experiment 4 then evaluates how a battery of measures from the language environments of children with cochlear implants predict discrimination accuracy. Together, these studies innovatively respond to the question of how early language experience may improve speech outcomes for children with cochlear implants. The combination of in-lab experimentation with naturalistic portraits of children’s everyday learning environments will rigorously isolate which components of the home environment are most beneficial for these children’s speech development. More broadly, results will characterize the early language learning environment (adult input and self-auditory feedback) and demonstrate how early auditory disruptions,...