In 2013, Johns Hopkins University researcher and epidemiologist Dr. Frank Lin guided a study that was the first to evaluate the possible impact of hearing loss on mental performance.
Research volunteers with hearing loss took recurring cognitive assessments, used to quantify memory and thinking skills, over the course of six years. Hearing tests were also carried out over the same time period.
What the researchers found was concerning: the cognitive abilities of those with hearing loss declined 30 to 40 percent faster than those with normal hearing, even after accounting for other contributing factors like high blood pressure, age, and diabetes.
But that wasn’t everything. Not only did people with hearing loss experience higher rates of cognitive decline—the decline was directly connected to the degree of the hearing loss. The more extreme the hearing loss, the greater impairment to brain performance. Additionally, those with hearing loss showed signs of appreciable cognitive impairment 3.2 years sooner than those with average hearing.
The research shows a strong connection between hearing loss and cognitive decline, but the question remains as to how hearing loss can trigger cognitive decline.
How Hearing Loss Creates Cognitive Decline
Researchers have proposed three reasons for the relationship 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 invest too many resources to the processing of sound, at the expense of memory and thinking.
- A shared underlying injury to the brain causes both hearing loss and diminished brain function.
Perhaps it’s a mix 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 be done 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 counter cognitive decline?
Can Hearing Aids Help?
Recall the three ways that hearing loss is believed to cause accelerated cognitive decline. Now, contemplate how hearing aids could address 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 cognitive decline—are mitigated or eliminated.
- Hearing aids prevent the overtaxing impact of struggling to hear. Cognitive resources are freed up for memory and thinking.
- Hearing aids generate boosted sound stimulation to the brain, helping to re-establish neural connections.
Admittedly, this is only theoretical, and the big question is: does using hearing aids, in fact, slow or prevent accelerated mental decline, and can we measure this?
The answer could be discovered in an upcoming study by Dr. Frank Lin, the head researcher of the initial study. Lin is presently working on the first clinical trial to examine 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.