Assessing Access to Language in the Real-World and Neural Language Processing in Preschoolers who are Deaf or Hard of Hearing - Abstract Children who are Deaf or Hard of Hearing (CDHH) developing spoken language are at risk of language delays. Language difficulties in CDHH are partially explained by hearing status factors (i.e., age of amplification) as well as reduced exposure to caregiver language input. Recent models of language acquisition emphasize that noise in the environment can further limit access to caregiver input. Thus, the premise of this work is that CDHH exposed to both limited caregiver input and reduced access to language, face the highest risk of language delays. Our long-term goal is to study longitudinally effects of overall language experiences on CDHH's behavioral and neural language development. In this proposal, we recruit a heterogenous group of 40 preschool CDHH and an age-matched control group of children with typical hearing (CTH). We aim to develop and assess the effectiveness of a novel Speech Accessibility Index (SAI). The SAI is designed to quantitatively evaluate children's access to language in real-world environments (Aim 1). In addition, we aim to assess the feasibility of evaluating preschooler's neurophysiological correlates of language processing in noise using alpha power (Aim 2). We hypothesize that the SAI will be effective explaining variability in language skills in both groups, and that children will engage cognitive and language areas of the brain (reflected in alpha power modulations) to effectively listen to sentences in noise. This research uses novel ecologically valid measures of children's auditory environments as well as cutting-edge electroencephalography analyses. Thus, we provide an innovative methodology that holistically examines early language experiences, neural mechanisms involved in language processing in real-world environments, and associations of these factors with preschooler's behavioral outcomes. Thus, we will enhance our comprehension of factors affecting language acquisition in CDHH and CTH. Moreover, the study will trigger the development of auditory-based intervention strategies aiming to facilitate access to language in the real-world for CDHH. Therefore, this research has the potential to improve long-term lifelong outcomes of CDHH.
