Age-related hearing loss is the third most common chronic health condition affecting adults in the United States, following hypertension and arthritis and has recently been identified as a risk factor for cognitive decline and dementia. Despite its high prevalence within older adults and its association with dementia, age-related hearing loss remains largely underexplored and unaccounted for in the neuroscience of aging literature. Thus, it is unclear how hearing loss may contribute to brain aging. With this study, we aim to examine how hearing loss impacts brain structure and brain function, and how the APOE-e4 gene (a known risk factor for developing Alzheimer's disease) may influence these relationships. Our findings could point to novel intervention targets to combat brain aging and Alzheimer's disease, including the use of hearing aids, which may provide neuroprotective effects against hearing loss.