Hearing Aids and Cognitive Decline: The Research
In 2013, Johns Hopkins University researcher and epidemiologist Dr. Frank Lin directed a study that was the first to assess the possible impact of hearing loss on mental performance.
Research volunteers with hearing loss took recurring cognitive tests, used to evaluate memory and thinking skills, over the course of six years. Hearing tests were also conducted over the same time frame.
What the investigators 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 all. Not only did those with hearing loss suffer from higher rates of cognitive decline—the decline was directly related to the intensity of the hearing loss. The more extreme the hearing loss, the greater deterioration to brain performance. In addition, those with hearing loss showed symptoms of significant cognitive deterioration 3.2 years earlier than those with average hearing.
The research reveals a strong connection between hearing loss and cognitive decline, but the question persists as to how hearing loss can create cognitive decline.
How Hearing Loss Creates Cognitive Decline
Researchers have proposed three explanations for the association between hearing loss and cognitive decline:
- Hearing loss can lead to social isolation, which is a known risk factor for cognitive decline.
- Hearing loss forces the brain to devote too many resources to the processing of sound, at the expense of short term memory and thinking.
- A common underlying trauma to the brain causes both hearing loss and decreased brain function.
Perhaps it’s a mix of all three. What is evident is that, regardless of the cause, the connection between hearing loss and cognitive decline is strong.
The question now becomes, what can we do about it? Experts estimate that 27 million Americans over age 50, including two-thirds of men and women aged 70 years and older, are afflicted by some kind of hearing loss. Is there a way those with hearing loss can avoid or overturn cognitive decline?
How Hearing Aids Could Help
Remember the three ways that hearing loss is considered to cause hastened cognitive decline. Now, think about how hearing aids could resolve or correct those causes:
- Individuals with hearing aids gain back their social confidence, become more socially active, and the problems of social isolation—and its contribution to brain decline—are mitigated or removed.
- Hearing aids protect against the fatiguing impact of struggling to hear. Cognitive resources are freed up and available for memory and reasoning.
- Hearing aids yield increased sound stimulation to the brain, helping to re-establish neural connections.
Admittedly, this is only theoretical, and the big question is: does wearing hearing aids, in fact, slow or protect against accelerated mental decline, and can we measure this?
The answer could be discovered in an forthcoming study by Dr. Frank Lin, the lead researcher of the initial study. Lin is working on the first clinical trial to examine whether hearing aids can be objectively measured to prevent or mitigate brain decline.
Stay tuned for the results, which we’ll address on our blog once published.