A long-term study followed older adults with moderate hearing loss. Hearing aids did not improve performance on tests of memory or thinking. Over seven years, people prescribed hearing aids were significantly less likely to develop dementia. Participants with hearing loss who wore hearing aids had a 61% lower risk of all cases of dementia. Those who did not use them had a 20% higher risk of dementia. Using hearing aids reduced the risk of developing dementia by up to 61 percent.