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In 2013, Johns Hopkins University researcher and epidemiologist Dr. Frank Lin directed a study which was the first to appraise the possible impact of hearing loss on brain function.

Volunteers with hearing loss took recurring cognitive exams, 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 investigators found was concerning: the cognitive abilities of those with hearing loss diminished 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 people with hearing loss suffer from higher rates of cognitive decline—the decline was directly related to the extent of the hearing loss. The more serious the hearing loss, the greater impairment to brain function. Furthermore, those with hearing loss exhibited signals of substantial cognitive impairment 3.2 years sooner than those with average hearing.

The research depicts a deep connection between hearing loss and cognitive decline, but the question remains as to how hearing loss can trigger cognitive decline.

How Hearing Loss Produces Cognitive Decline

Researchers have offered three reasons for the association between hearing loss and cognitive decline:

  1. Hearing loss can bring about social isolation, which is a well-known risk factor for cognitive decline.
  2. Hearing loss forces the brain to devote too many resources to the processing of sound, at the expense of short term memory and thinking.
  3. A common underlying injury to the brain causes both hearing loss and decreased brain function.

Perhaps it’s a collection of all three. What is apparent is that, irrespective of the cause, the connection between hearing loss and cognitive decline is powerful.

The question now becomes, what can be done about it? Researchers estimate that 27 million Americans over age 50, including two-thirds of men and women aged 70 years and older, are afflicted by some form of hearing loss. Is there a way those with hearing loss can prevent or overturn cognitive decline?

Can Hearing Aids Help?

Remember the three ways that hearing loss is believed to trigger more rapid cognitive decline. Now, consider how hearing aids could deal with or correct those causes:

  1. People that use hearing aids gain back their social confidence, become more socially active, and the effects of social isolation—and its contribution to cognitive decline—are mitigated or eliminated.
  2. Hearing aids prevent the overtaxing effect of struggling to hear. Cognitive resources are freed up for memory and reasoning.
  3. 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 wearing hearing aids, in fact, slow or protect against hastened 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 working on the first clinical trial to examine whether hearing aids can be objectively measured to protect against or mitigate brain decline.

Stay tuned for the results, which we’ll address on our blog once published.

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