Can Treating Hearing Loss Reduce Dementia Risk? Research Says Yes

For many years, researchers have been connecting the dots between hearing loss, cognitive decline, and Alzheimer's disease. More recently, scientists have come to recognize how hearing devices—including hearing aids and cochlear implants—may serve to mitigate cognitive decline while simultaneously improving quality of life for those affected.

The Link Between Hearing Loss and Cognitive Decline

According to Madeline Campbell, AuD, CCC-A, an audiologist with Baystate’s Audiology and Hearing Services, “Hearing loss has been identified as a significant risk factor for cognitive decline and dementia, particularly Alzheimer's disease. In fact, studies have shown that the risk of cognitive decline in older adults with severe hearing loss is five times greater than it is for individuals with normal hearing. Even for those with mild hearing loss, the risk of cognitive decline is two times greater.”

As for what’s behind the correlation, Campbell points to three factors: cognitive load, neural atrophy, and isolation.

She explains, “When hearing is impaired, the brain works harder to try to hear. This can take away resources that are usually used for thinking and memory. The extra burden, or cognitive load, causes the brain to work less efficiently.”

In addition, she says, “When the areas of the brain normally stimulated through hearing aren’t activated due to hearing loss, brain cells can be weakened. This neural atrophy can lead to changes in the brain structure which impacts how it performs.”

Finally, she notes, “Very often, people with hearing loss tend to withdraw from social situations where they find it frustrating not be able to actively participate in conversation and activities. Unfortunately, isolation is a known risk factor for dementia as it contributes to neural atrophy.”

Because age-related hearing loss often happens over the course of many years, it goes untreated as the deficit is perceived as normal.

“Again,” says Campbell, “untreated hearing loss increases the rate of cognitive decline and increases the risk of dementia by up to 20%. However, there are ways to reduce the risks.”

The Positive Impact of Hearing Aids and Cochlear Implants

Recent research has revealed that hearing aids and cochlear implants have the potential to do more than just restore hearing.

Campbell explains, “Because hearing devices reduce the burden on cognitive resources, areas of the brain that weren’t getting stimulated can once again become engaged. This leads to improved communication and hearing in social situations and increased opportunities to partake in brain-stimulating activities. In fact, one study found that the risk for dementia caused by hearing loss dropped from 20% to 70% when hearing loss is treated.”

Hearing Aids and Cognitive Decline

For individuals with mild to moderate hearing loss, hearing aids, which amplify sound, are a solid bet to re-engage the brain.

But, as Campbell notes, having a properly fitted hearing aid is key to its performance and deriving the maximum benefit from the device.

Specifically, she says, “A properly fitted hearing aid must be set to the right volume for an individual’s hearing loss. This allows for the best possible sound quality, reduced background noise, minimized feedback and/or whistling, and of course comfort. If you’re having issues with any aspect of your hearing aid, you’re not likely to get the full benefit or even wear it; both of which work against reducing cognitive decline risk. An audiologist can help you with a fitting and even choosing a style that works for your specific needs.”

Cochlear Implants and Cognitive Decline

However, for individuals with moderately severe to profound hearing loss, hearing aids can’t help.

“That’s where cochlear implants (CIs) come in,” says Jeanne Coburn, AuD, CCC-A/S, an audiologist at Baystate’s Audiology and Hearing Services.

Instead of amplifying sound, she explains, “CIs stimulate the auditory nerve to send signals to the brain where it’s recognized as sound.”

Surgically implanted behind the ear, CIs work by sending pulses of energy to the hearing nerve and bypassing the part of the ear that isn’t working. CIs, which can be implanted in one or both ears, are a common option forpeople of all ages who experience sudden hearing loss as well as those whose hearing ability has declined to the point where hearing aids no longer help.

Coburn says, “Unlike hearing aids, which you can purchase on your own at any time, you must qualify for a CI procedure. Testing typically takes 1.5 hours and is performed by an audiologist. If a patient currently has hearing aids, they should bring them to the testing facility as testing involves a standard hearing test and additional testing with hearing aids on.

“We’re looking to determine how profound the hearing loss is and how well a person can hear with an optimized hearing aid. If their word recognition score is less than 60%, they’re generally a candidate for a CI.”

If an individual is approved for a CI, the Baystate Hearing and Audiology team will help schedule the implant procedure with an ENT (an ear, nose, and throat doctor). The surgery can take 2 to 4 hours, with patients returning home once it’s done.

“While the improvement in hearing for patients with CIs can be profound, it takes time and practice,” says Coburn. “It’s not just about improving hearing; it’s about re-awakening parts of the brain that may have been dormant for a while. That can take a few days or even weeks.”

For the best results, patients are encouraged to:

• Use their CI for 10+ hours per day
• Practice listening on a daily basis by exposing themselves to conversations
• Make use of apps and programs designed to improve listening

Coburn points to research that demonstrates patients with poor cognitive function prior to a CI showed overall improved cognitive function and a slower rate of progress to dementia when compared to the general population after CI. In addition, patients with existing dementia who received a CI showed an average improvement in sentence understanding scores from 21% prior to implant to 44% post-procedure.

“The potential for hearing aids and CIs to help patients retain their hearing, cognitive abilities and quality of life is undeniable, but,” she notes, “they only work if you get them and use them.”

Seeking Treatment for Cognitive Decline and Hearing Loss

She encourages anyone showing signs of hearing loss or dementia (or both!) to reach out to their healthcare provider to schedule an appointment to be evaluated.

Early Signs of Dementia

• Short-term memory loss
• Often misplacing things
• Difficulty finding words
• Confusion or disorientation in a familiar place
• Increased irritability
• Impaired judgment

Early Signs of Hearing Loss

• Difficulty understanding others, especially in noisy environments when the speaker is not facing you
• Need to have others repeat themselves frequently for you to hear
• Listening to the television, radio or telephone at a volume louder than others
• Feeling frustrated or stressed during conversations due to the inability to hear

While hearing loss is common in older adults, it doesn’t have to just be tolerated. It can be treated, to address the difficulties of hearing loss and to reduce the risk of cognitive decline, dementia, and Alzheimer’s. Contact your healthcare provider today to set up a hearing test, a cognitive evaluation, or both.