Hearing Loss and Cognitive Decline

Hearing loss does not simply make conversation harder. Research increasingly points to it as a major contributor to cognitive decline and social isolation — and it is now considered one of the largest individual modifiable dementia risk factors identified by the Lancet Commission, alongside high LDL cholesterol.

A 12-year study of memory and processing speed

The Maastricht Aging Study, published in Alzheimer’s & Dementia in January 2024, followed participants with and without hearing loss over 12 years, tracking two specific cognitive measures: verbal memory and information processing speed. At the start of the study, both groups performed similarly. By year 12, a clear gap had opened up on both measures — participants without hearing loss maintained a higher predicted mean score than those with hearing loss, and the gap widened progressively over the follow-up period rather than appearing suddenly.

The same study also tracked cumulative incidence of cognitive decline over the 12-year period. By the end of follow-up, the hearing loss group had reached a cumulative incidence of roughly 27%, compared with approximately 19% in the group without hearing loss — a meaningful difference in how many people in each group had experienced measurable cognitive decline by that point.

Hearing loss as an independent risk factor

One of the more important findings to come out of this area of research is that hearing loss is a risk factor for cognitive decline independent of other dementia risk factors — meaning the association is not simply explained away by hearing loss tending to occur alongside other risks like older age or cardiovascular disease. A separate study, published in JAMA Network Open in 2019, examined the association between hearing loss and dementia specifically and reinforced this same conclusion: hearing loss carried its own distinct association with dementia risk, not just a byproduct of other overlapping factors.

Why hearing loss might drive cognitive decline

There are a few plausible mechanisms researchers point to, and they are not mutually exclusive:

• Cognitive load. When hearing is impaired, the brain has to work harder to process and interpret sound and speech, which may divert cognitive resources away from other tasks, including memory encoding.
• Reduced sensory input. Sound is one of the brain’s continuous streams of environmental information. Less auditory input over years may mean less overall stimulation to brain regions involved in processing and integrating sensory information.
• Social isolation. Hearing loss makes conversation and group settings more effortful, which can lead people to withdraw socially — and social isolation is itself an independently identified modifiable dementia risk factor in the Lancet Commission’s framework.

Because hearing loss likely acts through more than one of these pathways simultaneously, it is treated in current dementia-prevention research as a genuinely significant, and genuinely addressable, target — not a minor footnote.

What this means in practice

The practical implication of this research is fairly direct: hearing health deserves the same level of attention as other well-known dementia risk factors like blood pressure or physical activity. That means not dismissing gradual hearing changes as a normal, low-priority part of ageing, getting hearing checked periodically — particularly from midlife onward — and addressing hearing loss with appropriate aids or interventions when it is identified, rather than letting it go unaddressed for years.

Frequently asked questions

How much does hearing loss increase dementia risk? Earlier Lancet Commission analysis estimated the relative risk of cognitive impairment at roughly 2.0 for mild hearing loss and 3.0 for moderate hearing loss, making it one of the more substantial individual modifiable risk factors identified to date.

Does treating hearing loss (for example, with hearing aids) reduce dementia risk? The studies referenced here establish an association between untreated hearing loss and cognitive decline over time; they do not evaluate hearing aid use directly. That said, since hearing loss is classified as a modifiable risk factor, addressing it through appropriate means is a reasonable, low-risk step to discuss with a doctor or audiologist.

Is the link between hearing loss and cognitive decline just because both are more common in older age? No — research specifically finds that hearing loss is associated with dementia risk independently of other risk factors, meaning the relationship holds even after accounting for age and other overlapping factors.

How early should hearing be checked as part of dementia prevention? The Lancet Commission classifies hearing loss as a midlife risk factor, suggesting that checking and addressing hearing changes from midlife onward — rather than waiting until later in life — is the more evidence-aligned approach.

This article is for general information only and does not constitute medical advice. If you are experiencing hearing changes, consult a doctor or audiologist for proper assessment and management.