The short version
- In 567 older adults in rural South Africa, hearing impairment carried about 2.5 times the odds of dementia after adjusting for other factors.
- The predicted probability of dementia was 5% with no sensory impairment and 34% with hearing, distance vision and near vision all impaired.
- The study followed people for two years and cannot show that hearing loss causes dementia or that treating it prevents it.
A study in the journal Alzheimer’s & Dementia, published in 2025 and reported by Hearing Health & Technology Matters on October 6, tests the link between hearing loss and dementia in 567 older adults in the Agincourt sub-district of Mpumalanga Province, South Africa, drawn from the long-running HAALSI aging study.
Almost half, 47%, met the study’s definition of hearing impairment. Among participants with dementia the figure was 70%. Among those with normal cognition it was 36%. After adjusting for other factors, hearing impairment was associated with roughly 2.5 times the odds of dementia, and among people who were cognitively unimpaired at the start, it predicted dementia two years later.
Senses also added up. The predicted probability of dementia was 5% for people with no sensory impairment and 34% for those with impaired hearing, distance vision and near vision together. Nearly two-thirds of participants had impaired near vision.
This is an observational study with a two-year follow-up. It shows that poor hearing and dementia travel together in this community. It does not show that one causes the other. The press account does not say how hearing impairment was measured.
The authors’ own conclusion is practical: “Our findings highlight the need for targeted interventions to improve vision and hearing function.”
