In 2013, Johns Hopkins University researcher and epidemiologist Dr. Frank Lin directed a study which was the first to examine the possible impact of hearing loss on mental performance.
Participants with hearing loss took repeated cognitive tests, used to assess memory and thinking skills, over the length of six years. Hearing tests were also performed over the same time period.
What the researchers discovered was concerning: those with hearing loss had cognitive abilities that declined 30 to 40 percent faster than those with normal hearing, even after accounting for other contributing factors like age, high blood pressure, and diabetes.
But that wasn’t everything. Not only did those with hearing loss suffer from higher rates of cognitive decline—the decline was directly associated to the severity of the hearing loss. The more extreme the hearing loss, the greater impairment to brain function. Additionally, those with hearing loss presented signals of significant cognitive deterioration 3.2 years sooner than those with average hearing.
The research demonstrates a strong association between hearing loss and cognitive decline, but the question remains as to how hearing loss can result in cognitive decline.
How Hearing Loss Triggers Cognitive Decline
Researchers have proposed three reasons for the link between hearing loss and cognitive decline:
- Hearing loss can lead to social isolation, which is a well-known risk factor for cognitive decline.
- Hearing loss forces the brain to commit too many resources to the processing of sound, at the expense of memory and thinking.
- A shared underlying trauma to the brain causes both hearing loss and diminished brain function.
Perhaps it’s a collection of all three. What is evident is that, irrespective of the cause, the connection between hearing loss and cognitive decline is powerful.
The concern now becomes, what can we do about it? Experts estimate that 27 million Americans over age 50, among them two-thirds of men and women aged 70 years and older, are suffering from some kind of hearing loss. Is there a way those with hearing loss can prevent or overturn cognitive decline?
How Hearing Aids Could Help
Remember the three ways that hearing loss is thought to cause hastened cognitive decline. Now, consider how hearing aids could address or correct those causes:
- People with hearing aids increase their social confidence, become more socially active, and the consequences of social isolation—and its contribution to mental decline—are lessened or eliminated.
- Hearing aids protect against the overtaxing effect of struggling to hear. Cognitive resources are freed up and available for memory and thinking.
- Hearing aids deliver elevated sound stimulation to the brain, helping to re-establish neural connections.
Admittedly, this is mainly theoretical, and the big question is: does using hearing aids, in fact, slow or protect against accelerated mental decline, and can we quantify this?
The answer could be discovered in an upcoming study by Dr. Frank Lin, the lead researcher of the initial study. Lin is currently working on the first clinical trial to study whether hearing aids can be objectively measured to prevent or minimize brain decline.
Stay tuned for the results, which we’ll address on our blog once published.