How and Why to Learn Your Hearing Numbers

It’s just a fact of life: As we get older, our hearing declines, little by little.

Although many of us have noticeable hearing loss by the time we’re in our 40s, most of us don’t act on it until later in life, when someone convinces us it’s time for hearing aids, says Frank Lin, director of the Cochlear Center for Hearing and Public Health.

“Right now, the problem with hearing loss is that it becomes like a life event to get a hearing aid,” he says. But “if you treat hearing as just a metric that changes over your lifetime, you can begin using various technologies across your lifetime to help you hear and communicate better.”

Through the Know Your Hearing campaign, that’s what Lin, MD, PhD ’08, wants to empower people to do: to understand and track their hearing so they can do something about it when they notice changes.

Why Hearing Changes Over Time

We are born with all the inner-ear cilia—microscopic hair cells that move in response to sound waves—we’ll ever have. These cilia convert sound waves into electrical signals that travel along the auditory nerve to our brain, where they’re deciphered into what we identify as sounds.

Once these cells are damaged or die—whether the cause is illness, certain medications, genetics, exposure to loud noises, or by simply wearing out over time—they cannot regenerate. The loss is permanent.

In addition, our auditory nerve contains multiple fibers that decrease in number as we age and with overexposure to noise. The loss of these fibers makes it harder to distinguish, say, the voice of a person speaking to you in a busy restaurant.

Why It’s Important to Know How Well You Hear

For most people, hearing is tested early in life: before leaving the hospital after birth, before entering school, during childhood health check-ups, as part of in-school screenings.

Early in his career, Lin noticed that “if tests showed a mild loss for kids, the response was, ‘Oh, this is critically important to how well Little Susie can learn in the classroom or play on the playground,’” he says. “But if we were to scratch off Susie’s age and say she’s 75 years old instead of 7, there would be a collective shrug.”

Using hearing aids slowed the loss of thinking and memory abilities by 48% over three years in older adults at increased risk for cognitive decline.

That is starting to change, thanks to research establishing the connection between hearing loss and dementia.

In 2023, for example, a study by Lin and colleagues found a 61% greater prevalence of dementia among older adults with moderate to severe hearing loss than among those with normal hearing.

Why is that the case? Lin suggests several possibilities. When people are struggling to hear and fill in gaps to make sense of incomplete sounds, it may tap brain resources otherwise spent on memory or other cognitive functions. Hearing loss may make people less likely to engage socially, depriving them (and their brain) of important intellectual stimulation. It’s also possible that hearing loss causes more rapid shrinking of the aging brain.

The good news is that intervening to improve hearing can slow the progression of dementia. Lin and colleagues published findings from the ACHIEVE (Aging and Cognitive Health Evaluation in Elders) study showing that using hearing aids slowed the loss of thinking and memory abilities by 48% over three years in older adults at increased risk for cognitive decline.

So, we have evidence that hearing is important for brain health beyond childhood. We have widely available interventions in the form of over-the-counter hearing aids and even smartphone apps to help us hear better (see below). Now, Lin and colleagues at the Cochlear Center want to make sure people have the tools to understand their hearing so they can act when it changes over time.

What Is Your Hearing Number?

One common result of hearing tests is what is called the pure-tone average for each ear. Those numbers, known clinically as the PTA4 and commonly called the “Hearing Numbers,” are a measure in decibels of the softest speech sound a person can hear. The higher the number, the lower that person’s ability to hear.

Thanks to smartphone apps like the Hearing Number app recently launched by the Bloomberg School for iOS and Android, “in four or five minutes with your smartphone and in the privacy of your house, you can put in earbuds and learn your Hearing Numbers,” Lin says. This app joins other hearing tests that allow iPhone users to test their hearing and learn their PTA4, such as the built-in Apple hearing test available for use with AirPods Pro.

Everyone’s Hearing Numbers will increase over time—a fact that Lin hopes will be normalized. “If people began thinking about and tracking that number, much like they might know their step count or blood pressure and say, ‘Oh, I need to do something about that,’” says Lin, “it can change how people think and engage around their hearing.”

Download the Hearing Number app

App Store (iOS)Google Play (Android)

Then, trying new strategies or technologies to protect or optimize your hearing becomes no different from using reading glasses when you need them.

“That’s what we want to see,” says Lin, “so that the change we all experience over time is built into our understanding of hearing, and these technologies become ubiquitous. They’re everyday technologies.”

Enhance Your Hearing

Whether you’ve measured your hearing with an app, had a test at an audiologist’s office, or just noticed that you’re not hearing as well in certain situations, consider some of the following strategies:

• Control the physical setting. Get closer to the person you’re speaking with and have the conversation face-to-face. If possible, turn down background music or other competing noise, or move to a quieter space to talk.
• Use the tech you’ve got. Turn on subtitles or closed captioning for watching TV so you don’t struggle to fill in missing words. Explore your smartphone for settings to make it easier to hear music, podcasts, and phone conversations.
• Use hearing aids. In addition to traditional hearing aids available over the counter and by prescription, new takes on this technology are becoming increasingly available. Apple’s AirPods Pro 2, for example, have a hearing aid feature, and eyeglasses with integrated and invisible hearing aids are projected to soon become available as well.

Protect Your Hearing, Starting Now

No matter what your Hearing Number or age, it’s important to protect your hearing and reduce exposure to loud noises. Even if you’ve experienced some hearing changes, you can reduce further damage to inner-ear cells with simple interventions:

• Control your exposure. Turn down the volume when you can, such as when listening to headphones and earbuds. Avoid extended exposure to noisy environments. Many smartphone apps are available to measure environmental sound in decibels; you can use this information to decide whether to limit time in such settings, wear ear protection, or both.
• Wear ear appropriate protection in loud places like stadiums, shooting ranges, and concert venues, and when operating loud equipment like lawn mowers and power tools. A wide variety of earplugs that reduce decibels but preserve sound quality are available for concerts. For settings where the goal is to reduce all sound, noise-canceling earmuffs or well-fitting foam earplugs may be a better choice.

Melissa Hartman is managing editor of Hopkins Bloomberg Public Health magazine and director of editorial in the Bloomberg School’s Office of External Affairs.

Related:

• The Importance of Knowing and Optimizing Your Hearing Health…At ANY Age (podcast)
• Hearing Aids May Slow Dementia Onset
• New Study Links Hearing Loss With Dementia in Older Adults (news release)
• Hearing Loss and the Dementia Connection
• Cochlear Center Will Test Whether Treating Age-Related Hearing Loss Can Delay Dementia