PROJECT SUMMARY/ABSTRACT Cochlear implantation is the standard of care for patients with bilateral severe-to-profound sensorineural hearing loss. CI outcomes are primarily assessed using word and sentence recognition, which, although important, do not capture the diverse listening and communication experiences of CI users. Moreover, outcomes reported using these test batteries are often are poorly correlated with CI user self-report of real- world communication abilities. The lack of a universally accepted CI-specific patient reported outcome measure (PROM) to assess functional outcomes and quality of life (QOL) is a critical barrier to further our understanding of the way in which cochlear implantation influences communication, social, emotional, and other experiences of adult CI users. The long term goal of this research is to expand outcomes related to cochlear implantation beyond those narrowly defined by speech recognition, to provide a more comprehensive understanding of how cochlear implantation impacts its users. The overall objective of the current proposal is to determine the impact of cochlear implantation on patient QOL by validating and applying a new, disease- specific CI-QOL instrument. Our central hypothesis is that changes in CI-specific QOL as revealed through this novel instrument will strongly correlate with disease-specific outcome measures, but only weakly correlate with changes in speech recognition. Based on compelling preliminary results, our hypothesis will be tested by completing two specific aims: 1) Validate a newly developed QOL instrument for adult CI users following established procedures that meet rigorous psychometric standards; and 2) Assess longitudinal changes in CI- related outcomes and their associations during the first year after CI activation. Aim 1 will be completed in accordance with the guidelines developed by NIH’s Patient-Reported Outcomes Measurement Information System (PROMIS). In Aim 2, participants will complete the new CIQOL instrument and other outcome measures corresponding to the final domains of the validated CIQOL instrument before implantation and at intervals throughout the first 12 months post implantation. This work is innovative as it creates a new QOL instrument using a theoretical framework and approaches that have never been applied to the adult CI population. Additionally, our longitudinal study is innovative as studying the individual components that comprise QOL in the CI population and determining how each impacts overall QOL has not previously been investigated. The results will also provide critical preliminary data for future research aimed at identifying individual patient characteristics that impact CI outcomes, developing patient-specific strategies and rationale for performance improvements (such as new implantation techniques, listening modalities, and processing strategies), and making better estimates of the health utility and economic impact of cochlear implantation. ...