This project examines how to improve speech understanding with cochlear implants (CIs), particularly for older CI recipients. While older individuals benefit from CI technology, performance is poorer than that of younger implanted adults for difficult listening tasks. The mechanisms that contribute to this variability are not well-understood. The current project examines how differences in brain structure and function may contribute to success with a cochlear implant. To compare, we will also be examining how older patients without cochlear implants understand speech in difficult listening situations.