The Connection Between Hearing Loss and Dementia
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Loss of hearing can lead to difficulties communicating, social isolation, issues with balance, and reduced quality of life. In addition, untreated hearing loss may be linked to an increased risk of cognitive decline, including Alzheimer’s disease and other forms of dementia.
In fact, a study from Johns Hopkins University found that participants with severe hearing impairment were five times more likely to develop dementia than those without.
What happens during hearing loss?
According to the CDC, about a quarter of adults age 65+ have difficulty hearing or are unable to hear at all.
Hearing loss can occur when tiny hair cells lining the inner-ear, other parts of the ear, or nerves that relay information about sounds to the brain are damaged.
Normal hearing is often defined as the ability to hear sounds above about 25 decibels, or the sound of a whisper. For reference, the volume of a normal conversation is usually around 60-70 decibels. However, there are degrees of hearing loss, and it can range from mild to severe.
Some people may experience some symptoms of hearing loss without obtaining a clinical diagnosis – this is referred to as subclinical hearing loss. Even subclinical hearing loss has been found to be associated with impaired memory and thinking.
Research suggests that hearing loss may account for up to 9% of dementia cases worldwide. A study of adults aged 40-69 in the UK found that people with hearing loss who did not use hearing aids were likelier to develop dementia than those without hearing loss. However, people who used hearing aids did not have this increased risk.
Impacts on the brain
Researchers are striving to understand the complex ways in which hearing loss impacts the brain.
Brain imaging has shown that regions like the temporal lobe, a key player in sensory information processing and memory, can become damaged and shrink with hearing loss.
Loss of access to daily life’s rich ecosystem of sounds can create a less stimulating environment, which can impact brain function and structure. In turn, this may heighten dementia risk.
On the other hand, some studies have suggested that people with hearing loss must dedicate brain resources like attention, working memory, and language processing to listening. This may deplete these resources for other memory and thinking tasks.
Finally, hearing loss can interfere with social interaction, making it difficult to connect with others. As we discussed in our recent newsletter on loneliness, loneliness and social isolation can also play a role in a person’s risk for developing Alzheimer’s disease, and regular social engagement can help those living with the disease.
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Having hearing loss does not guarantee a person will develop dementia. Using hearing aids can help reduce risk.
If you’re concerned about hearing loss, encountering issues understanding others in conversation, or need the volume on your television turned way up, it’s important to consult with a medical professional.
