The Connection Between Hearing Loss and Dementia
Hearing loss can manifest as a sudden or gradual change in one's ability to hear. Individuals experiencing hearing loss may encounter challenges in everyday conversations, particularly in noisy environments. Dementia, on the other hand, is a broad term encompassing a group of symptoms that affect cognitive abilities such as thinking, memory, and reasoning, thereby impacting daily living activities.
It's essential to understand the relationship between hearing loss and dementia, as research indicates a significant connection between the two. This article delves into the link between hearing loss and dementia, exploring the underlying mechanisms, risk factors, and potential interventions.
Illustration showing the connection between hearing loss and dementia.
Understanding the Terms
Cognitive decline is a general term that can be used to describe common effects of brain aging. Even healthy aging may include a slow decline in memory and thinking abilities. Dementia is a syndrome that can impact memory and thinking abilities, particularly activities of daily living or social functioning. It may affect judgment, problem solving, and even personality.
Of the early signs of dementia, some minor changes may be expected indications of slight cognitive decline. Many communication difficulties related to hearing loss can cross-over with difficulties related to dementia. If adults are uncertain which dysfunction may be causing difficulties, it is recommended to seek evaluation from an audiologist (for hearing) and a physician.
The Link Between Hearing Loss and Dementia
Research indicates a strong association between hearing loss and an increased risk of developing dementia. Several studies have explored this connection, revealing compelling evidence.
- Untreated hearing loss increases the risk for dementia (Livingston et al., 2020).
- Adults with hearing loss have a faster rate of cognitive decline than adults with normal hearing (Lin et al., 2013).
A large piece of work looked at all the things that are related to an increased risk of developing dementia. When assessing a risk factor, researchers look at the number of people who develop dementia who have that risk factor, compared to those who don’t. In this case, researchers analysed many studies and showed that hearing loss is one of twelve main factors that leads to the highest risk of developing dementia.
Nearly double the amount of people with mild hearing loss (at the World Heath Organization threshold for diagnosis of hearing loss) will develop dementia compared to those without hearing loss. The risk tripled with moderate hearing loss and was nearly five times with severe hearing loss.
Even low levels of hearing loss have been associated with increased dementia risk and a decrease in memory and thinking skills. Are you having a little trouble hearing conversations? If so, you're not alone. An estimated 23% of Americans ages 12 and older have hearing loss. But not only is moderate to severe hearing loss disruptive to one's life, it also makes you more likely to develop dementia.
Also, unlike previous research, this study looked objectively at hearing loss and dementia. Prior research had shown that hearing loss is thought to account for about 8% of all dementia cases worldwide. It's important to note that most large studies that found this link were based on questionnaires that people fill out. In this new study, however, the investigative team used an electronic tablet-based audiometer to evaluate participants' hearing for four pure tone frequencies that are most important for understanding speech.
People who develop hearing problems during mid-life (aged 40-65) may have an increased risk of developing dementia. However, whether or not someone develops dementia depends on many other factors besides their hearing. Regardless of any possible link with dementia, it’s important to get your hearing tested to support living well day-to-day.
How Hearing Loss Impacts Cognitive Function
Several mechanisms may explain the link between hearing loss and cognitive decline:
- Cognitive Resource Depletion: Hearing loss demands extra cognitive (thinking-related) resources, which limits the cognitive resources that are available for memory and thinking.
- Brain Changes: There are also documented changes in the brain as a result of hearing loss (Lin et al., 2014); these changes are thought to impact cognition over time.
- Social Isolation: Additionally, hearing loss can lead to a decrease in social engagement (Weinstein & Ventry, JSHR, 1982), which is a known risk factor of dementia. People with hearing problems may also be more likely to withdraw from social situations and become more isolated over time. Social isolation and depression are both risk factors for dementia.
- Increased Brain Effort: Hearing loss may also mean that the areas of the brain that help us understand sounds and speech have to work harder to understand what sounds are.
There is increasing evidence that the more the brain is stimulated, the less likely it is that dementia will develop. When there is hearing loss, auditory stimulation is reduced. This, by itself, likely increases dementia risk. But even more important is that when an individual suffers from moderate to severe hearing loss, they are less likely to participate in social activities. Perhaps they are embarrassed about their hearing loss. It turns out that social activities are one of the best ways to stimulate the brain, as there is evidence that our brains evolved to facilitate social behavior. Given all this information, you won't be surprised to learn that reduced social activity has been linked to cognitive decline.
The Role of Hearing Aids
Hearing aids are a type of amplification device used to manage hearing loss. Recent research indicates that for people at greater risk of developing dementia, using appropriately fitted hearing aids reduces the risk of cognitive decline as compared to people who are high risk and who did not use hearing aids in the same 3-year period (Lin et al., 2023).
There is some evidence that, if needed, using hearing aids may reduce cognitive symptoms and slow cognitive decline in people at risk of dementia, though it’s not yet clear if using hearing aids can prevent dementia.
Hearing aid use was also associated with fewer memory problems and thinking problems independent of dementia. Tracking hearing aid use over a long period showed that it was associated with less decline in memory skills.
Several benefits are associated with using properly fitted hearing aids:
- Properly fit hearing aids are known to reduce listening effort, allowing for more cognitive resources to be available for other brain tasks.
- Hearing aids can also re-stimulate areas of the brain that have been neglected due to hearing loss.
- Lastly, hearing aids are known to improve social communication, which may prevent or delay dementia.
For patients diagnosed with dementia, hearing loss should be considered and treated. In early dementia, and with patients who have in-tact support systems, hearing aids may still be a good treatment option. For patients without the option of hearing aids, there are other assistive listening devices that could be helpful, such as remote microphones.
Hearing aids can help reduce cognitive decline.
Prevention and Early Detection
Protect your hearing to reduce dementia risk. Often, managing hearing loss works best when you start doing it early on. This means protecting your hearing from a young age. For example, you can avoid listening to loud noises for long periods and wear ear protection when necessary. Keep your ears clean. (But remember, never put anything in your ears smaller than your elbow. If you can't hear and you don't have hearing aids, get them. All these things will help to reduce your risk of dementia.
Age-related hearing loss and dementiaAge-related hearing loss is a common condition affecting older people. It often starts with problems hearing what other people say, especially in noisy environments. Symptoms can start gradually and be difficult to notice. This makes early detection and treatment difficult.
Types of Hearing Loss
There are two types of hearing loss: peripheral hearing loss and central hearing loss.
- Peripheral hearing loss is the reduced abilities of the ears to detect sounds. This does increase a person’s risk of developing dementia.
- Central hearing loss involves problems with processing sounds in the brain, that are not able to be corrected with hearing aids. This may be a very early symptom of Alzheimer’s disease, as sound processing parts of the brain are affected by the disease.
What to Do If You Suspect Hearing Loss
If you are concerned about hearing loss, the next step is to schedule a hearing test with an audiologist. You may be able to book a free hearing test at your local optician or speak to your GP about being referred to an audiologist (a doctor for hearing). This will show up any hearing issues and provide ways of managing them, such as using a hearing aid. The audiologist will be able to determine presence, type, and severity of hearing loss.
Key Findings from Research Studies
Here's a summary of findings from key research studies:
| Study | Key Finding |
|---|---|
| Lin et al. (2013) | Adults with hearing loss experience a faster rate of cognitive decline compared to those with normal hearing. |
| Lin et al. (2023) | Appropriately fitted hearing aids reduce the risk of cognitive decline in individuals at greater risk of developing dementia. |
| Livingston et al. (2020) | Untreated hearing loss increases the risk of dementia. |
If you have hearing loss, does that mean you're doomed to develop dementia? Not at all. Remember that hearing loss is only a risk factor.