The Connections Between Hearing Loss and Dementia
Hearing loss at any age carries its own set of challenges. However, hearing loss for seniors can be quite debilitating. This disabling condition can rob older adults of their freedom and make simple tasks a chore.
In many ways, hearing loss can make seniors feel alone and isolated. As conversations become more and more difficult to manage, this social isolation can leave them feeling like they’re on the outside looking in.
While hearing loss affects older adults in much higher numbers, some wonder if there could be a connection between hearing loss and cognitive function in seniors, specifically dementia.
Here, we hope to explore the connection between age-related hearing loss and dementia.
What Is Age-Related Hearing Loss?
According to data by the National Institute on Deafness and Other Communication Disorders, hearing loss affects around one in three people between the ages of 65 and 74 in the United States.
Nearly half of those over the age of 75 live with some degree of hearing loss.
This age-related hearing loss is called presbycusis. Age-related hearing loss is one of the most common conditions that affect seniors and is responsible for the largest segment of hearing aid purchases.
Age-related hearing loss can present a real stumbling block for many older adults.
Aside from the difficulty in daily conversation, it can make it difficult to understand and follow a doctor’s advice. Furthermore, hearing loss can make it difficult for seniors to hear smoke alarms, doorbells, and more.
In short, untreated hearing loss can leave older adults with feelings of loneliness and isolation. This is especially true for those without caregivers or advocates looking out for their well-being.
Sensorineural Hearing Loss and the Inner Ear
Age-related hearing loss is a type of sensorineural hearing loss.
This type of degenerative hearing loss occurs slowly over time as we age and the structures in the auditory system are damaged. Most of the damage occurs in the inner ear portion of the auditory system.
The inner ear is extremely important for healthy hearing. It comprises the cochlea, interconnected semicircular canals, hair cells, and nerves.
These components help capture sound vibrations from the middle ear and transmit them as electrical impulses to the brain through the auditory nerve.
Age-related hearing loss occurs due to damage to inner ear hair cells and the auditory nerve. This damage is often permanent and requires amplification devices like hearing aids or surgical interventions like cochlear implants to restore some degree of hearing.
According to Johns Hopkins, symptoms of age-related hearing loss can include:
- Difficulty hearing on the phone.
- Speech sounding slurred or muffled.
- Tinnitus (ringing in the ears).
- High-pitched voices are harder to discern.
- Difficulty discerning where sounds are originating.
- Conversations are hard to follow in environments with background noise.
There are degrees of hearing loss, ranging from mild to severe.
These degrees use decibels (dB) to measure. Normal hearing ranges from 0 to 20 dB. Mild to moderate hearing loss tops out around 55 dB, while more severe forms go well beyond.
Hearing tests with a hearing health care provider in the audiology field, such as an audiologist or ENT, will measure and determine these decibel levels.
Other Causes of Sensorineural Hearing Loss
Aside from aging, long-term exposure to loud noise is another risk factor for hearing loss.
Noise-induced hearing loss is common for those who’ve worked in construction and factory environments.
Ototoxic medications can also put older adults at increased risk for developing hearing loss.
Other potential causes for sensorineural hearing loss include Ménière’s disease, tumors, and cochlear otosclerosis.
Hearing Loss and Dementia: Are They Connected?
Studies have shown that there may be a connection between hearing loss and dementia. What is the connection? Does one contribute to the other?
What Is Dementia?
Rather than being a specific disease, dementia is a blanket term that houses a host of neurological conditions that affect the brain.
Alzheimer’s disease is one example and represents the most common type of dementia.
Dementia is essentially a loss of cognitive function.
These cognitive functions include things like reasoning, thinking, and remembering. Over time, this cognitive decline can disrupt someone’s overall quality of life.
The risk of dementia is greatest in older adults. According to the World Health Organization (WHO), dementia affects roughly 55 million people worldwide — with 10 million new cases yearly. Alzheimer’s disease represents about 60 to 70 percent of dementia cases. The prevalence of developing dementia is highest among those over 80.
Cause and Symptoms of Dementia
In short, damage to brain cells causes dementia, though it’s far more complicated.
This brain atrophy damage interferes with brain function, specifically the brain cell’s ability to communicate with one another. Different forms of dementia determine what part of the brain is affected.
The signs and symptoms of dementia vary by stage, from early to late stages, and are marked by their severity, from mild cognitive impairment to more severe forms.
Most symptoms include sharp declines in cognitive abilities, such as memory, attention, communication, and overall reasoning.
But what is the connection between hearing problems and dementia? Do hearing impairments like age-related hearing loss equal increased risk of dementia? Let’s take a closer look at this relationship between hearing and mental health.
How Is Hearing Loss and Dementia Related?
While the research is ongoing, new reports show a strong connection between hearing loss and dementia.
Dr. Frank Lin, director at Johns Hopkins’ Cochlear Center for Hearing and Public Health, believes hearing loss and dementia could have a much closer relationship than previously thought.
One report in particular shows some interesting findings. According to the 2020 Lancet Commission report, hearing loss represents a “midlife modifiable risk factor” for dementia, especially for those between the ages of 45 to 65.
The report estimates that hearing loss accounts for roughly eight percent of dementia cases.
Possible Connections Between Hearing Loss and Dementia
Research suggests hearing loss makes the brain work more as it strains to hear. This, in turn, removes cognitive power from other important systems, such as memory or thinking.
One theory suggests that hearing loss may contribute to brain atrophy and aging, causing it to shrink prematurely.
Another theory states that hearing loss could contribute to dementia because it makes older individuals less socially engaged. When the brain is not intellectually stimulated, cognitive decline is possible.
Could Hearing Aids Help Reduce the Risk of Dementia?
One of the key questions researchers seek to uncover is the potential for hearing aid use to reduce the risk of someone developing dementia.
One prospective study in the Lancet report found an increased dementia incidence among those who self-reported hearing issues—except for those who wore hearing aids.
Currently, otolaryngology and neurology studies are seeking to examine more closely the connection between hearing loss and cognitive decline treatments. The data from those studies are still forthcoming.
Age-related hearing loss remains one of the most common conditions among older adults. Cognitive disorders like dementia are also high among the same age demographic.
This correlation has caused many researchers to ask, “Is there a connection?”
While research into hearing loss and cognitive decline is still ongoing, there is promising evidence to suggest that a strong connection between the two is possible.