In 2013, Johns Hopkins University researcher and epidemiologist Dr. Frank Lin directed a study that was the first to analyze the potential consequence of hearing loss on mental performance.
Volunteers with hearing loss took repeated cognitive assessments, used to measure memory and thinking skills, over the course of six years. Hearing tests were also completed over the same time frame.
What the researchers discovered was concerning: the cognitive abilities of those with hearing loss decreased 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 linked to the extent of the hearing loss. The more serious the hearing loss, the greater deterioration to brain functioning. Additionally, those with hearing loss showed signs of substantial cognitive impairment 3.2 years earlier 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 generate cognitive decline.
How Hearing Loss Triggers Cognitive Decline
Researchers have offered three explanations for the link between hearing loss and cognitive decline:
- Hearing loss can contribute to social isolation, which is a recognized risk factor for cognitive decline.
- Hearing loss forces the brain to commit 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 diminished brain function.
Perhaps it’s a mixture of all three. What is apparent is that, irrespective of the cause, the link between hearing loss and cognitive decline is powerful.
The concern now becomes, what can we do about it? Researchers estimate that 27 million Americans over age 50, among them two-thirds of men and women aged 70 years and older, experience some type of hearing loss. Is there a way those with hearing loss can prevent or counter cognitive decline?
How Hearing Aids Could Help
Remember the three ways that hearing loss is thought to trigger hastened cognitive decline. Now, contemplate how hearing aids could address or correct those causes:
- People with hearing aids restore their social confidence, become more socially active, and the problems of social isolation—and its contribution to brain decline—are lessened or removed.
- Hearing aids protect against the fatiguing impact of struggling to hear. Cognitive resources are freed up for memory and thinking.
- Hearing aids provide amplified sound stimulation to the brain, helping to re-establish neural connections.
Admittedly, this is mainly theoretical, and the big question is: does utilizing hearing aids, in fact, slow or prevent 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 alleviate brain decline.
Stay tuned for the results, which we’ll address on our blog once published.