ABSTRACT – HUMAN ECOLOGY – PROJECT 4 Cochlear implants (CIs) improve speech recognition for adults with moderate to severe hearing loss; however, many CI users report significant struggles in their natural listening environments. This is understandable as speech recognition in complex daily environments are likely to be affected by challenges that are not present in the sound booth (e.g., high reverberation and accented speech). Indeed, many listeners with CIs report that difficulty in real-world listening leads to fatigue, stress, and social isolation. CI clinical care has traditionally focused measures of speech recognition assessed in clinic with the assumption that broader outcomes like quality of life (QoL) will directly follow. The past literature has shown that lab/clinical measures of speech recognition are only modestly correlated with QoL, suggesting that the factors that impact speech recognition in the lab are likely to differ from those that affect speech perception and QoL in CI users’ everyday lives. The primary goals of the proposed project are to identify challenging listening situations that CI users encounter in daily life and to examine factors that predict real-world speech perception and QoL over and above what is measured in the clinic. The study focuses on the role that CI users’ auditory environments, higher order cognitive skills, and social networks play in real-world listening success and QoL. The project includes cross-sectional and longitudinal components that combine Ecological Momentary Assessments (EMA) of real world listening, neuropsychological measures across cognitive domains, and analysis of individuals’ social networks. Aim 1 will describe the complexity and challenges of auditory environments encountered in daily life for CI users using objective data collected using ear-level microphones and self-reports via EMA. We will identify differences in the auditory environment across individuals of varying age, geographic location, occupational status, and race, and explore the impact of differences in hearing (e.g., pre- vs. post-implantation) on the environments one engages in. Aim 2 will identify factors that predict success with speech perception in the real world (assessed using EMA). This includes data about the auditory environment collected from Aim 1, and a neuropsychological battery spanning multiple higher-order cognitive domains. We propose that the auditory environment and cognitive function will explain unique variance in real- world speech perception, after controlling for the effect of peripheral auditory function and speech perception measured in the lab. Aim 3 will determine the factors that drive good QoL after implantation. We propose that speech perception in the real world, higher order cognitive skills, and social network characteristics (e.g., social support and social integration) will play a more important role in driving QoL than speech perception measured in the lab.