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As research into aging and cognition advances, one connection has become harder to ignore: the strong correlation between hearing loss and cognitive decline, including dementia. While recent studies, such as the ACHIEVE trial, have shown promising results indicating that hearing aids may slow this decline—especially among those most at risk—researchers are still working to determine the underlying cause.
Now, a new theory may offer fresh insight. A team of audiologists, neuroscientists, and a physician has proposed the Cognitive Maladaptation Hypothesis—a model suggesting that the brain’s attempts to adapt to sensory deprivation from untreated hearing loss might, over time, backfire and contribute to cognitive impairment. This new idea builds on—and in some ways challenges—several older hypotheses about how hearing loss affects the brain.
The article, “The Cognitive Maladaptation Hypothesis: How sensory deprivation could contribute to cognitive decline,” appears in the May 12, 2025 edition of the Journal of Otolaryngology-ENT Research and is authored by Hannah Glick, AuD, PhD, Douglas Beck, AuD, Keith Darrow, PhD, and Jung Trinh, MD.
The brain is remarkably adaptable. When sensory input—like sound—is attenuated, distorted, or minimized due to hearing loss, the brain reconfigures its neural circuits in an effort to maintain function. This process, known as neuroplasticity, can sometimes compensate for reduced hearing by increasing reliance on context, memory, and visual cues.
For example, in the presence of significant hearing loss, regions of the temporal lobe which are no longer being stimulated by sound may be taken over by other neural networks such as vision. This “cross-modal recruitment” may have benefits, as it adapts and compensates for hearing loss by maximizing the sensory input available from vision.
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However, according to the authors, this neural compensation may come at a cost. Over time, these adaptive changes may become maladaptive, resulting in the inaccurate processing of sensory input, increased mental effort, and greater cognitive fatigue. Rather than simply filling in the blanks, the cognitive maladaptation hypothesis suggests that the brain may recalibrate in response to suboptimal input from hearing and vision, thereby causing confusion and straining cognitive resources. This, in turn, may accelerate cognitive decline, especially in individuals who already have vulnerabilities like those with less education, mild cognitive impairment (MCI), depression, diabetes, or cardiovascular disease, and perhaps patients with polypharmacy issues.
One study cited in the article, for example, found that adults with untreated age-related hearing loss showed earlier frontal-lobe responses on auditory tests—and those early responses were linked to worse speech-in-noise understanding. In other words, the brain might be “jumping the gun,” trying too hard to compensate, but doing so inefficiently.
The result? A possible vicious cycle: untreated hearing and/or vision loss may lead to brain changes, which reduce auditory and visual processing efficiency and increase mental strain, ultimately contributing to long-term degradation and cognitive issues.
“As of this writing, none of us has clear or indisputable evidence with regard to the veracity of any of the many available hypotheses,” coauthor Dr. Douglas Beck told HearingTracker. “Eventually, some, all, or none may prove to be true. In the meantime, all we can do is try to rationally understand the degradation process of the human brain as it relates to cognitive decline, to better prevent the same in years to come.”
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Before the Cognitive Maladaptation Hypothesis, several other theories have been proposed to explain the hearing-cognition connection. Each shines a light on a different part of the puzzle:
Any or all of these factors could help explain why hearing loss is associated with cognitive decline/dementia. However, there are limitations, as some fail to explain fully why people with no other health issues develop both hearing loss and dementia. Others don’t account for the wide variability in who experiences cognitive decline, or how brain structure (i.e., anatomy) and function (i.e., physiology) adapt to long-term auditory deprivation.
The authors suggest that current models may not fully capture the dynamic, brain-based consequences of untreated hearing loss. The Cognitive Maladaptation Hypothesis helps fill this gap by focusing on how the brain’s attempts to “reorganize” itself in response to degraded hearing can backfire, particularly over months, years, or decades.
Importantly, this hypothesis aligns with emerging evidence from neuroscience and audiology:
This framework also helps explain why early hearing care intervention may be so important. Once maladaptive neural patterns become entrenched, they may be more difficult to reverse—especially for older adults with limited cognitive reserve or reduced neuroplasticity.
“As the Livingston et al's Lancet studies indicate, the more effective diagnosis and intervention period likely occurs in middle age—before neuroplastic and neuropathy damage has occurred,” says Beck. “In essence, it seems easier to maintain function than to try to recreate it later.”
Although the Cognitive Maladaptation Hypothesis remains a theory, it raises important clinical questions. Could untreated hearing loss alter the brain in ways that increase dementia risk? Can timely treatment—such as properly fitted hearing aids—prevent or even reverse these changes?
Findings from the ACHIEVE study offer a promising glimpse. For older adults who had health problems and were at greater risk of cognitive decline, the use of hearing aids over 3 years was associated with nearly 50% less cognitive decline compared to a control group. While more modest effects were seen in healthier participants, longer-term studies may reveal benefits over time. This adds weight to the call for early proactive care.
The current study authors emphasize that comprehensive audiometric assessment, early diagnosis, and timely treatment may not only improve communication but could also support long-term brain health. Moreover, it places more urgency on coordination between audiologists, neurologists, geriatricians, and primary care providers. Integrating speech-in-noise testing and cognitive screening into routine hearing care protocols may help identify high-risk individuals earlier and guide more personalized care. These protocols are already identified as within the scope of practice for audiologists by the American Academy of Audiology (AAA) and American Speech-Language Hearing Association (ASHA).
The connection between hearing loss and cognitive decline is no longer a fringe idea; it’s a well-supported correlational relationship. But exactly how hearing loss might contribute to that decline is still under investigation.
The Cognitive Maladaptation Hypothesis offers new insights: one that views the brain’s adaptive response to hearing loss not always as helpful, but sometimes as detrimental. If true, this would underscore the urgent need for early hearing care intervention—not just to help people hear better, but to support healthier aging and cognitive function.
"I think the key to cognitive health as we age has a lot to do with maintaining and preserving brain health via the two primary sensory inputs to the brain: vision and hearing,” says Beck. “It is no longer acceptable to simply screen hearing or vision; we need the details. It is no longer acceptable to say, 'Your hearing loss is normal for your age.' That’s ridiculous. After 42 years as an audiologist, I feel very confident saying hearing loss is common, but it is not normal. There is no 'normal for your age' diabetes, 'normal for your age' lower back pain, migraines, or sleep deprivation. These conditions may be common, but they are not normal.”
Original article citation: Glick HA, Beck DL, Darrow K, Trinh J. The cognitive maladaptation hypothesis: how sensory deprivation could contribute to cognitive decline. J Otolaryngol-ENT Res. 2025;17(2). Published online May 12, 2025.
Karl Strom ist der Chefredakteur von HearingTracker. Er war Gründungsredakteur des The Hearing Review und berichtet seit über 30 Jahren über die Hörhilfeindustrie.
