ABSTRACT Jennifer A. Deal is an epidemiologist and gerontologist, with a position as Assistant Scientist in the Department of Epidemiology, Johns Hopkins Bloomberg School of Medicine and a secondary appointment in the Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine. She seeks a mentored career development award to fill knowledge gaps in her current training so that her research can successfully bridge the diverse fields of cognitive aging, audiology, otolaryngology, epidemiology and cognitive neuroscience in order to improve the health of older adults. The primary component of the training proposal includes a comprehensive five-year plan of formal and informal instruction in the acquisition, processing and analysis of neuroimaging data (structural MRI and PiB PET) in large population-based studies. The PI will also augment current knowledge about the collection and analysis of hearing data in epidemiologic studies with additional training in the clinical aspects and pathophysiology of hearing impairment. The training program consists of didactic coursework and seminars, clinic observations, and mentored research by an established and diverse team of experts. Short-term career goals include completion and dissemination of high-quality mentored research through publications and presentations and application for independent R01 funding beginning in the fourth year of the award period. Long-term career goals are to be an independent investigator in the area of aging and cognitive decline and dementia, with expertise in hearing impairment. The specific aims of the proposed research are to quantify the independent association of HI incident dementia and with domain-specific cognitive decline in three well-characterized prospective observational studies, to investigate the relationship of HI with changes in brain volume over time (both in regions related to Alzheimer's disease and to auditory processing), and to quantify the role of vascular factors in the development of HI. Completion of the proposed aims will elucidate the role and mechanism of hearing impairment in dementia and domain-specific cognitive decline, providing possible targets for future clinical research with the potential to inform efforts to prevent these adverse outcomes in older adults.