We are currently recruiting adults with normal hearing (ages 40-70 years) and adults (ages 40-70 years) with suspected age-related hearing loss in the Boulder and Denver-Metro Area to participate in the Hearing Aid Plasticity Intervention (HAPI) Project. The HAPI Project is a new study funded by the Hearing Industry Research Consortium to examine the effects of well-fit amplification with hearing aids on brain plasticity, cognitive function, and speech perception. All participants will receive a free hearing test. Hearing loss participants will be fit with state-of-the-art hearing aids by an experienced, licensed audiologist for free to up to a year. We will study brain changes over time in adults with hearing loss over the course of amplification use.