This study investigates the prospective association between hearing loss and the incidence of all-cause dementia and Alzheimer's disease (AD) in a cohort of 639 participants from the Baltimore Longitudinal Study of Aging. The study found that hearing loss is independently associated with an increased risk of incident all-cause dementia and AD. The risk of all-cause dementia increased log-linearly with the severity of baseline hearing loss, with a hazard ratio (HR) of 1.89 for mild hearing loss, 3.00 for moderate hearing loss, and 4.94 for severe hearing loss compared to normal hearing. The study also estimated that over one-third of the risk of incident all-cause dementia was attributed to hearing loss in participants aged >60 years. The findings suggest that hearing loss may be a modifiable risk factor for dementia and highlight the importance of addressing hearing loss in older adults to potentially reduce the risk of cognitive decline and dementia.This study investigates the prospective association between hearing loss and the incidence of all-cause dementia and Alzheimer's disease (AD) in a cohort of 639 participants from the Baltimore Longitudinal Study of Aging. The study found that hearing loss is independently associated with an increased risk of incident all-cause dementia and AD. The risk of all-cause dementia increased log-linearly with the severity of baseline hearing loss, with a hazard ratio (HR) of 1.89 for mild hearing loss, 3.00 for moderate hearing loss, and 4.94 for severe hearing loss compared to normal hearing. The study also estimated that over one-third of the risk of incident all-cause dementia was attributed to hearing loss in participants aged >60 years. The findings suggest that hearing loss may be a modifiable risk factor for dementia and highlight the importance of addressing hearing loss in older adults to potentially reduce the risk of cognitive decline and dementia.