Are you repeating points your senior loved one missed hearing the first time? Are you finding the need to turn the TV up louder for him or her? Are they talking more loudly?
Hearing loss in seniors is not uncommon. Nearly 38 million Americans experience hearing loss to some extent. Further, two-thirds of adults over 70 exhibit some level of hearing loss.
The bigger question is whether hearing loss is linked to dementia. A number of recent studies have indicated a prevalence of dementia among the participants with moderate to severe hearing loss to be as much as 61 percent higher than the prevalence among participants who had normal hearing. This significant correlation between having untreated hearing loss and cognitive decline warrants considerable attention.
Older adults with hearing loss have a decline in cognitive functioning at a rate 30 to 40 percent faster than those with normal hearing. That being said, the likelihood of dementia was lower among hearing aid users compared to non-users.
A 2015 study at the University of Colorado shows that in reaction to hearing loss the brain reassigns its parts that normally processes hearing to do other tasks and, as a result, reducing cognition. Subsequent studies have confirmed this finding. Further, this can occur with only minor hearing loss.
Using electrodes attached to the scalp, researchers measured brain activity in reaction to sounds with both adults and children with varying levels of hearing loss utilizing EEG recordings of brain activity.
Measuring brain waves in the speech and language processing center of the brain (the auditory cortex), researchers were able to compare how well the auditory center responded to certain sounds.
By comparing the results between participants with mild to severe hearing loss or deafness with those with no hearing loss they found that among those with hearing loss some had brains that “hijacked” the low-functioning auditory cortex and reassigned its function for other purposes.
According to Hearing Review, “The areas of the brain responsible for processing vision or touch can recruit areas in which hearing is normally processed, but which receive little or no stimulation in deafness. This cortical reorganization reflects a fundamental property of the brain to compensate in response to its environment.”
Additional hypotheses include:
- Hearing loss causes an older brain to shrink more rapidly.
- A brain that has to focus harder to strain to hear and to fill in the gaps when communication is missed, impacts the brain’s memory and thinking systems.
- Decreased social interaction results in less mental stimulation and a less active and engaged brain.
Even if a patient receives hearing aids or a cochlear implant, their results depend on the extent to which the auditory cortex has been “hijacked” because it is less able to process sound.
The question arises, how soon should someone be concerned with this “brain reorganization”?
Since the brain can start this reorganization with only mild hearing loss, regular hearing checks should be conducted regularly for anyone over the age of 55. Age-related hearing loss, where the hearing center of the brain shrinks and other parts of the brain step in to compensate, create a deficit when the brain should be doing other important things like decision making at a high level. Such a situation can overwhelm the brain and increase the possibility of cognitive decline.
The best way to prevent cognitive loss and keep the auditory cortex functioning as it should is to get hearing treatment as early as possible – certainly at the earliest indication of hearing loss. Just getting a hearing test is critical for older people. Even if the test does not show significant hearing loss, it provides a baseline for future examinations.
If a senior you love has difficulties with hearing loss, encourage them to get a checkup and to wear hearing aids if recommended by the doctor. The impact on his or her life goes way beyond being able to hear.