Audio expert examines whether noise-cancelling headphones help or harm ears

Recent headlines in the United Kingdom earlier this year attributed noise-canceling headphones as a possible culprit in rising rates of auditory processing disorder (APD) and hearing problems in younger populations. While the APD theory is interesting, it’s speculation that’s not backed up by the data, according to a campus audiologist.

However, the resulting media attention does raise awareness of the problem of APD, which occurs when the brain has trouble discerning sound differences, especially in noisy environments, and is treatable. It also puts the spotlight on the popular noise-canceling headphones and their pros and cons.

“Ultimately, what we’re most concerned about is the sound level at your ear in your headphones,” said Cory Portnuff, AuD, Ph.D., assistant clinical professor in the Department of Otolaryngology—Head and Neck Surgery at the University of Colorado School of Medicine.

“One of the advantages of active noise-cancellation headphones is that you may not need to turn your headphones up to avoid external sound, as long as you make sure you know what’s happening around you.”

In the following Q&A, Portnuff explains the technology behind noise-canceling headphones, what auditory processing disorder is and how it is treated.

How do noise-canceling headphones work?

Noise-canceling headphones are designed to reduce background noise by electronically canceling steady noise signals. There are two types of noise-canceling:

• Active noise-canceling works by creating an inverse sound wave that actually gets rid of—cancels out—external sound in real time.
• Passive noise isolation works by physically blocking out external sounds, either with something that seals around your ear or an earplug.

When does noise-canceling technology work best? Where does it struggle?

Noise-canceling headphones work really well for steady background noise—think the engine noise of an airplane. This noise is predictable for fast-moving digital algorithms to easily get rid of.

Digital noise cancellation or active noise cancellation is not as good at canceling out external sounds that are variable noises. These include things like people talking, traffic or public transportation. There’s a lot of squeaks and bangs and other loud sounds that are harder to predict in those cases. Some noise-canceling algorithms can be adjusted even, so you can use an app on your phone to adjust how much it’s going to try to block out somebody talking, for example.

Our noise-cancellation headphones have gotten a lot better over the years though. Every year we see significant improvements in the ability of systems to cancel exterior sound. Higher-end pairs, however, are better at blocking those variable noises.

Can noise-canceling headphones help protect hearing?

Noise-canceling headphones are not good at protecting hearing from loud sounds. For example, noise-canceling headphones are not good enough to be protective from damaging your hearing around loud sounds like a lawnmower or light construction work.

They can help you be able to lower the volume on your music, podcasts or whatever you’re listening to so you don’t have to turn it up so high. Which is good—we don’t want people to rely on active noise-cancellation for hearing protection.

What are auditory processing disorders?

They are disorders of how the brain interprets sound—more specifically, how the brain deals with all of the challenging components of hearing. For example, there are auditory processing disorders that have to do with how we hear between two ears, or how we pull speech out of background noise or how we deal with rapid speech.

How does someone get an auditory processing disorder, and what are their symptoms?

Auditory processing disorders are generally something that happens from birth, though there are acquired auditory processing disorders that happen related to injuries to the brain or aging.

When we think about symptoms of auditory processing disorders, we primarily think about people who have difficulty hearing in challenging listening environments but can still hear all the sounds around them like they normally should.

A classic example is kids in classrooms who can hear all of the soft sounds around them but have a hard time filtering out the teacher’s voice from the noise of kids around them. Or when there are two conversations happening at once, someone is having a hard time being able to home in on just one.

They are more common in populations of people who might be considered neurodivergent. People with autism spectrum disorder, for example, frequently have auditory processing disorders. Additionally, it’s sometimes hard to differentiate an auditory processing disorder from a cognitive impairment. So if you have an injury to your brain, you may have both auditory processing impairments as well as impairments in thinking and memory, and they kind of go together a lot.

What did you make out of the news this year (out of the United Kingdom) that attributed noise-canceling headphones as a cause of auditory processing disorder?

The theory behind that is that if you grow up not exposing your brain to challenging listening environments, you don’t develop those skills. Or if you use a lot of noise cancellation, perhaps you would have some atrophy in your ability to pull speech out of background noise.

While that’s an interesting theory, there’s no evidence that this is happening. We are not seeing this necessarily in our clinical practice, and we’re not seeing this at a larger scale in any of our epidemiologic research.

Would you say this is a case of correlating diagnosis with increased awareness of APD?

There’s certainly more awareness of auditory processing disorders today than there was 20 years ago.

One of the amazing things that the internet has allowed us to do is connect people with low-incidence disabilities and disorders together and help spread the word about different symptoms that may be related to a disorder that we can name. That’s great for patients. Patients can access care better when they know what’s going on.

Also, it’s challenging, because it makes some things look more common than they are. Auditory processing disorders are definitely one of those where we see no changes in rates of auditory processing disorders, but it’s becoming more commonly identified or at least self-identified.

How do you test for auditory processing disorder?

While we have minimal research in the world of biomarkers and genetics about auditory processing disorders, we can test for auditory processing disorders quite easily. In the clinic, we typically start with a standard hearing test, and if we identify loss of hearing, then we move on from there. If we don’t identify loss of hearing on our typical behavioral hearing tests, then we can do additional testing to look at people’s strengths and weaknesses in auditory processing.

Auditory processing testing is going to look at some more of the higher-level functions of hearing. How do you hear when you’re hearing two different words in different ears? How do you hear in a noisy environment? How do you process sound when it’s very rapid noises? Basically, what we call the temporal processing of sound.

What does treatment for APD look like?

There are therapies that are effective at treating auditory processing disorders. Mostly we use auditory training programs, sort of like physical therapy for your ears.

We have some pretty good efficacy on treating auditory processing disorders using combinations of auditory training programs. Hearing aids actually can help with auditory processing disorders when fit to help with a mild hearing loss. Also, remote microphone technology where somebody else could wear a microphone that sends sound directly to your ear can be helpful.

Bottom line: If you have an APD, we have a variety of different things that can be done to help you quite reasonably.