Brain Health & Hearing

Protecting Your Brain Starts With Protecting Your Hearing

Hearing loss is the single largest modifiable risk factor for dementia — and treating it is one of the most powerful steps you can take to protect yourself from dementia as you age.

#1 — Modifiable risk factor for dementia (Lancet, 2024)
7% — Of dementia risk could be prevented by addressing hearing loss (Lancet, 2024)
48% — Enhanced cognitive functions with hearing aids (Lin et al., 2023)
62% — Slower cognitive decline in high-risk adults regularly using hearing aids (Pike et al., 2025)

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Why Hearing Loss Threatens Your Brain

When you lose the ability to hear clearly, your brain pays a steep price — and the damage begins long before any dementia diagnosis.

Scientists have identified three key pathways through which hearing loss accelerates cognitive decline. First, the brain’s auditory cortex becomes starved of input and starts to shrink — a process called brain atrophy. Second, decoding degraded sound signals forces the brain to work overtime, diverting cognitive resources away from memory and executive function while still requiring your cognition to function as normal, leading to a chronic overload. Third, people with hearing loss tend to withdraw socially, and social isolation, which takes away essential stimulation for the brain, is itself an independent risk factor for dementia.

Multiple research has consistently supported that adult-onset hearing loss increases the risk of incident cognitive decline including the 2024 Lancet Commission’s report on Dementia. Yu et al., (2024) research provided an exact figure that every 10 decibel (dB) decrease in hearing ability increases dementia risk by up to 24% — and that the evidence for treating hearing loss has grown stronger with every major new study.

Toronto Hearing Services has prepared a detailed Cognitive and Audiological Report for every adult hearing test with concerns of hearing loss.

Get your Cognitive and Audiological Report today

Three Ways Hearing Loss Harms the Brain

Brain Atrophy: "Use It or Lose It"

The brain’s auditory cortex depends on constant sound stimulation to maintain its volume and activity. Without it, grey matter in the regions responsible for speech and language processing shrinks measurably faster. Brain imaging studies confirm that people with untreated hearing loss show accelerated structural brain changes — the same regions implicated in early Alzheimer’s disease.

This shrinkage is not inevitable: restoring sound input through hearing aids has been shown to slow and, in some cases, partially reverse this atrophy.

Cognitive Overload: The "Exhausted Brain" Effect

When hearing is impaired, the brain must dedicate extraordinary effort just to understand what is being said. This constant extra processing — needing to fill in gaps, guess missing words, strain to follow conversations — drains the same cognitive bandwidth your brain uses for memory consolidation, attention, and executive function.

Over years, this chronic cognitive overload builds up extra brain waste. Combined with other factors that slow the removal of waste, the overload accelerates the depletion of cognitive reserve, leaving the brain more vulnerable to dementia.

Hearing aids directly reduce this load: when amplified sound reaches the brain clearly, listening becomes effortless again. Be it freeing up for higher-level thinking, or reducing waste produced, restoring your hearing helps prevent cognitive decline.

Social Withdrawal: The Loneliness Loop

Difficulty following conversations in group settings, restaurants, or on the phone causes many people with hearing loss to gradually stop participating. They decline social invitations, withdraw from family gatherings, and become increasingly isolated. Social isolation and loneliness are independently associated with more than a 50% increase in dementia risk (Donovan & Blazer, 2020) — comparable in strength to physical inactivity or untreated high blood pressure.

Clinical research such as ACHIEVE has confirmed that hearing aids help break this cycle: participants who received hearing aids showed 48% slower decline in cognition, and substantial improvements in communication ability, enabling them to stay socially and physically engaged.

Mechanism B — Reducing Cognitive Load → Freeing Up Brain Resources

When a hearing aid provides a clean sound signal, the brain no longer has to fill in gaps or strain through noise. This dramatically reduces the cognitive effort required for everyday listening. The result is less mental fatigue, better focus, and greater cognitive resilience over time.

How Hearing Aids Protect Your Brain

Modern hearing aids don’t just make things louder — they actively reverse the biological and social pathways that lead to cognitive decline. Here’s exactly how:

Mechanism A — Restoring Auditory Stimulation → Slowing Brain Atrophy

By delivering clear, amplified sound to the auditory cortex, hearing aids resume the stimulation that the brain needs to maintain its structure. Think of it like crutches for the brain — consistent, appropriate stimulation keeps neural pathways active and strong.
Of course, beyond the support from the outside, there is auditory training you need to do in order to train up your brain to process sounds again.

Mechanism C — Re-Enabling Social Engagement → Breaking the Isolation Loop

If you can’t understand, you can’t engage. That is the case of people with hearing loss. When people can hear clearly again, they return to the conversations, social settings, and activities they had avoided.

This renewed engagement stimulates the brain in exactly the way that protects against dementia — through meaningful interaction, intellectual challenge, and emotional connection. Participants who wore their hearing aids consistently showed the greatest cognitive benefits particularly in communication.

You can start supporting your brain health by taking annual hearing tests, or check out our tips on strategies to communicate better.

“The hearing intervention may slow down decline in thinking and memory by making listening easier for the brain, or by helping people remain more socially and physically active.”
— ACHIEVE Trial Researchers, Johns Hopkins University / Alzheimer’s Association International Conference, 2023

The Landmark Study That Changed Everything

The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) trial, published in The Lancet in 2023, was the first large-scale randomized controlled trial to directly test whether treating hearing loss could slow cognitive decline. Its findings made international headlines.

Key Stats:

~1,000 adults aged 70–84 enrolled in the randomized controlled trial (top level of scientific evidence)
3 years of follow-up
48% slower cognitive decline in older adults with more chronic illnesses
62% slower cognitive decline in the high-risk quartile

“Hearing loss is very treatable in later life, which makes it an important public health target to reduce risk of cognitive decline and dementia, along with other dementia risk factors such as less education in early life, high blood pressure, social isolation, and physical inactivity.”
— Dr. Frank Lin, MD, PhD — Johns Hopkins University, Co-Principal Investigator, ACHIEVE Trial

The ACHIEVE trial found that benefit was greatest in adults who already had cardiovascular risk factors or other health conditions — in other words, those at the highest risk of dementia are exactly the people who have the most to gain from hearing treatment. And the research was clear: consistent daily hearing aid use produced the greatest protective effect.

Lancet has also been researching factors behind dementia, and hearing loss remains the top modifiable risk, which means so long as you know how to treat your hearing loss, you lower your risk of getting dementia. Here’s how the relationship between hearing loss and dementia established over the years.

Hearing Loss Is the Biggest Lever You Can Pull

The Lancet Commission identified 14 modifiable risk factors that together could prevent up to 45% of dementia cases. Hearing loss sits at the top — responsible for more preventable dementia than any other single factor.

Risk Factors

Source: Population-attributable fractions, Lancet Commission on Dementia Prevention, Intervention, and Care (2024)

How Well Are You Caring for Your Brain?

The Brain Care Score is a free, evidence-based self-assessment developed by researchers at Mass General Brigham. It measures your brain health across 12 factors in three domains, with total scores from 0 to 21. The Brain Care Score measures how well you are caring for your brain in three domains: physical health, lifestyle, and emotional wellbeing.

Take your Brain Care Score quiz here.

The Brain Care Score is a self-screening tool, not a medical diagnosis. Always discuss your results with a qualified healthcare professional.

Hearing Health Is Brain Health

Of all the risk factors identified by research, hearing loss stands apart: hearing loss is highly treatable, available today, and immediately actionable. Every other modifiable risk factor — blood pressure, physical activity, diet — requires sustained lifestyle change over months or years. Hearing? You can begin protecting your brain the day you start wearing your hearing aids.

Learn more about the comprehensive diagnostic assessment here.

A comprehensive hearing assessment takes less than an hour. If hearing loss is detected, modern hearing aids are discreet, comfortable, and proven to begin protecting your cognitive health right away. The sooner you act, the greater the protection — because every year of untreated hearing loss is a year of unnecessary cognitive risk.

What a Hearing Assessment Includes:

Pure-tone audiometry (full hearing threshold test)
Speech recognition in quiet and noise
Middle ear and eardrum evaluation
Discussion of cognitive risk and lifestyle factors
Personalized treatment recommendations
Hearing aid fitting consultation if indicated

Frequently Asked Questions

Can hearing loss really cause dementia?

Hearing loss doesn’t “cause” dementia in the way a virus causes an infection, but it is one of the strongest risk factors for developing it. The 2024 Lancet Commission identified hearing loss as the single largest modifiable risk factor for dementia, accounting for an estimated 7% of all dementia cases globally — more than any other preventable factor.

The relationship works through three pathways: reduced auditory stimulation leads to brain atrophy; chronic cognitive overload from straining to hear depletes cognitive reserve; and communication difficulty leads to social isolation, which is itself a major dementia risk factor.

How much can hearing aids actually reduce my risk of dementia?

The most rigorous evidence comes from the ACHIEVE trial led by Dr. Frank Lin at Johns Hopkins, funded by the NIH. It found that hearing aids slowed the rate of cognitive decline by 48% in adults at higher risk of dementia. Among those in the highest-risk quartile, the benefit was even greater: cognitive decline was 62% slower. Separately, a 20-year Framingham Heart Study follow-up found that adults under 70 using hearing aids had a 61% lower risk of developing dementia.

At what age should I get my hearing tested?

The Lancet Commission highlights midlife hearing loss (ages 45–65) as the period of highest impact on lifetime dementia risk — this is the window where hearing aids offer the greatest protection. Audiologists in Toronto recommend a baseline hearing test by age 50, with follow-ups every 3–5 years. If you notice difficulty following conversations, frequently ask people to repeat themselves, or prefer higher TV volumes, don’t wait — book an assessment now regardless of age.

I have mild hearing loss. Do I still need hearing aids?

Short answer: Yes. The cognitive impact of hearing loss begins before it becomes severe, and the protective benefit of hearing aids is not limited to those with profound loss.

Mild hearing loss is often dismissed as “not bad enough to treat,” but from a brain health perspective, even modest hearing difficulties place measurable extra burden on the brain.

How do hearing aids protect the brain — what's the actual mechanism?

Hearing aids work through three complementary brain-protective mechanisms: (1) Restoring brain stimulation to maintain brain structure and prevent deterioration. (2) Reducing cognitive load so that it wouldn’t be overused. (3) Re-enabling social engagement to unlock one of the most protective forces against cognitive decline.

I already have some memory problems. Is it too late to benefit from hearing aids?

It is not too late. Research in individuals with mild cognitive impairment (MCI) found that hearing aid use was associated with a lower risk of progressing to full dementia. While hearing aids cannot reverse existing cognitive damage, they can meaningfully slow further decline by removing one of its key drivers. Treating hearing loss also improves quality of life, communication with family, and overall engagement with the world — benefits that matter regardless of dementia stage.

Does the type or brand of hearing aid matter for brain protection?

Current research does not point to a specific brand or technology type as superior for cognitive protection. What matters most is consistent, daily use, and most importantly, a professional fit to your hearing profile. A professional fitting and follow-up care are essential to ensure you’re getting the right device for your lifestyle and maximum cognitive benefit.

Are hearing assessments covered by insurance or provincial health plans in Canada?

Coverage varies by province. In Ontario, OHIP covers the standard hearing test when referred by a physician — but does not cover the cost of advanced diagnostic testing and hearing aids. Hearing aids may be partially covered through employer benefit plans, Veterans Affairs, or provincial assistive device programs.
Contact us directly and we’ll help you navigate what coverage may be available before your appointment.

How is a hearing assessment done — is it uncomfortable or time-consuming?

A comprehensive hearing assessment is completely non-intrusive and typically takes 45–60 minutes. It involves: wearing headphones and pressing a button when you hear tones; repeating words to test speech recognition; and a quick visual inspection of your ear canal and eardrum.
No needles, no discomfort, no preparation required. At the end, your audiologist will review your results in plain language and outline any treatment options appropriate for you.

Step By Step Procedure

What to Expect on Your First Visit

01
Get to Know You & Understand Your Symptoms

02
Discuss Your Treatment Goals & Medical History

03
Determine Your Stage of Hearing Loss/Tinnitus

04
Answer All of Your Questions or Concerns

05
Begin a Custom Treatment Plan

Start The Process Today

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CUSTOM TREATMENT PLAN

Begin Your Treatment Today

Don’t wait to take the next step toward better hearing and a better quality of life. Whether you’re looking to address hearing problems or book a hearing test, our clinics across Toronto are here to support you. 

From testing to treatment, our team will guide you through every step. Whether you’re just starting to notice changes or have been managing hearing loss for a while, we’re ready to help you find the right solution.

Schedule your consultation today and take the first step toward better hearing and a more connected living.