(Last Updated On: September 29, 2020)

We break down how noise cancellation works and whether are there any health complications.

Wide shot of headphones with soundwaves.
From: Gergana Valkova/123rf

For many of us, a pair of good quality, noise-canceling headphones is a welcome respite in a world that is noisier than ever. Sometimes, it feels so great to block out all the unnecessary disruptions of daily life that it’s tempting just to keep them on all the time.

But as lovely as that thought is, it’s no secret that many have reported adverse effects associated with prolonged use of noise-canceling headphones. Often, these experiences lead to questions of whether noise-canceling is safe and how much usage time is too much.

Not to worry, we’ve got all the nitty-gritty details laid out so that you can be better informed before buying your own.

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How Do Noise-Canceling Headphones Work?

Headphones use one of two types of noise cancellation – passive noise cancellation (PNC) or active noise cancellation (ANC). PNC headphones create a physical seal over the ear so that you hear less background noise. On the other hand, ANC electronically produces an opposing frequency that cancels out ambient noise altogether.

To understand how this all works, let’s get into the mechanics of noise cancellation.

Passive noise cancellation

Passive noise cancellation is the most common form of noise cancellation that most headphones in the market employ.

PNC headphones, particularly the over-ear or circumaural types, work by physically soundproofing the ears using specific materials. The ear cups of PNC headphones create an airtight seal over the ear, preventing sound from leaking out or coming in, and high-density material like memory foam further dampens unwanted noise.

PNC headphones are more effective against temporary high-frequency sounds, such as sirens, barking dogs, screaming kids, honking cars, etc. That said, it’s more accurate to call PNC headphones as “noise-isolating” headphones because they only physically block out external noise without actually ‘canceling’ them.

Active noise cancellation

Active noise cancellation uses a sophisticated system that electronically manipulates external sound to cancel it out.

Active noise cancellation begins with a miniature microphone sampling the ambient noise in your surroundings. If you’re sitting in a crowded coffee shop, for example, the microphone will pick up the sound waves generated by the constant drone of the busy cafe. These soundwaves are basically pressure waves that travel through the air at a specific frequency.

The microphone then takes the sampled audio and feeds it into the battery-powered noise-canceling system in the headphones. The system then inverts it, producing a signal that is the exact opposite of the original. This new opposite signal is then played back to us through the headphone speakers.

Here’s where it gets a bit more technical. When two frequencies or signals are in complete opposition to each other, that means they are in antiphase. And when two signals in antiphase collide, destructive interference occurs.

Illustration of the interference of two waves (From:Wikimedia Commons).
Illustration of the interference of two waves (From: Wikimedia Commons).

Destructive interference occurs when the highest point of one frequency meets the lowest point of its opposing frequency (seen in the left image), thereby canceling them both out. This contrasts with what we see in the rightmost image (constructive interference) wherein the two frequencies are identical, resulting in a more amplified signal.

In sum, ANC headphones produce opposing frequencies that cancel out the frequencies of the ambient noise around you, resulting in silence.

So, Is Noise-Canceling Safe?

The short answer is, yes. Noise-canceling headphones, on their own, are safe. In fact, noise-canceling headphones can be beneficial in helping prevent hearing loss and alleviating noise-related stress.

As previously mentioned, noise-canceling headphones work by removing continuous low-frequency background noises like the hum of machinery or an airplane engine’s rumble. With this noise significantly reduced, the wearer experiences clearer sound and no longer feels the need to raise the headphones’ volume to ear-damaging levels.

Noise-canceling headphones can also help with noise-related stress. This type of stress doesn’t just disrupt our concentration but can also cause high blood pressure, ulcers, and migraines. Having a good pair of noise-canceling headphones helps minimize our exposure to bothersome background noise and helps keep our stress levels in check.

Safety Concerns Involving Noise-Canceling Headphones

Man wearing headphones on a city sidewalk (From:Unsplash).
Man wearing headphones on a city sidewalk (From: Unsplash).

Despite the benefits of noise-canceling headphones established, a simple Google search will tell you that there have been several safety-related user complaints regarding the said devices. The good news? Most of these issues can easily be addressed or explained.

Let’s talk about some of the most common safety concerns involving noise-canceling headphones.

Pressure on the ears

Some of the most common complaints surrounding noise-canceling headphones involve jaw pain, headaches, dizziness, and ear pressure. The ear pressure, in particular, is likened to the same kind of ear pressure one feels on an ascending airplane. To understand this better, it’s essential to know how barometric pressure changes affect us.

When we take off in a plane, the ear pressure we feel occurs because of air density differences inside and outside your ears. When air density is higher inside your ears, the inner ear vibrates less, which means you perceive low-frequency sounds less.

We know that ANC headphones cancel out low-frequency sounds, so sometimes, using them here on solid ground can trigger the brain into thinking that there’s been a pressure change, resulting in headaches and the feeling of having pressure in the ears.

Some people adapt well to ANC headphones and don’t experience any symptoms at all. Others can use them without incident for only a few hours a day before they feel the need to take them off. Unfortunately, there is no “cure” for this, and people who struggle with the symptoms are left with no choice but to trade their ANC headphones for PNC ones instead.

Tinnitus

Tinnitus is a persisting ringing or buzzing sound in the ears that becomes even more pronounced with the lack of any external background noise. It’s a common disorder that can affect people of all ages and can be triggered by anything that damages or interferes with your ears’ sensitive internal structures.

Many people have reported experiencing tinnitus due to using ANC headphones, however, there is no scientific correlation between tinnitus and ANC headphones. A plausible theory for the perception of tinnitus is likely due to the heightened noise reduction by ANC headphones. As ambient noise is lessened, we become hyper-aware of ringing sounds in our ears.

On the contrary, ANC headphones are recommended for tinnitus sufferers, as well as for the prevention of tinnitus. This is because the effective ambient noise cancellation feature reduces the need for wearers to increase the volume of their headphones when in noisy environments, thus preventing or lessening any future tinnitus episodes.

Close up of the Calmer in-ear device (From:Flareaudio.com).
Close up of the Calmer in-ear device (From:Flareaudio.com).
Those living with noise-related stress, tinnitus, or generally sensitive hearing could benefit significantly from a product called Calmer. Designed by Flare Audio, Calmer is a non-electrical, silicone device placed in the ear. It works by reducing and dampening the ear-jarring distortion that mid-frequency sounds often have.

Using noise-canceling headphones outdoors

Not having music to motivate you through a workout, or your favorite podcast to accompany you on an errand sounds inconceivable. But it’s this singular act of putting on a pair of noise-canceling headphones while we’re out and about which places millions of people at risk every year.

For many of us, it’s second nature to don a pair of headphones before we head out, but in doing so, we’re hampering one of the most important senses we need to recognize danger. We close ourselves off from mentally registering things like sirens, car horns, fire alarms, and other important danger alerts, thereby increasing our chances of getting into an accident.

If you’re driving or running along an area with lots of traffic, it’s advisable to avoid using noise cancellation altogether.

Such activities require the attentiveness of all our senses and will often need a lightning-fast response from us if something goes wrong.

US states like Colorado, Maryland, Louisiana, and Rhode Island in particular, have even outrightly banned the use of any type of headphones while driving. But even if it’s legal in other states, it is still highly discouraged.

To lessen the occurrence of distraction-related accidents, tech companies like Audio Analytic created ai3™, a sound recognition software designed to be embedded into audio devices, like headphones, earphones, and speakers. This allows users to be alerted with certain sounds (car horns, sirens, alarms) even while wearing ANC headphones, thus allowing them to react accordingly.

We reached out to Audio Analytic to ask more about which products feature their software. According to Marketing VP Neil Cooper, there are currently no products in the market that are outfitted with their tech; however, they do expect to see devices soon.

Conclusion

Yes, we all love our games, our music, and our quiet time, but let it not be at our hearing’s expense. Our ears are fragile, and we only get one pair of these babies in a lifetime, so it’s up to us to treat them well. Hopefully, with this in-depth guide, we’ve not only helped you understand how to get the most out of your headphones but also how to take care of your ears.

Got any questions, tips, or suggestions? We’d love to hear anything you’d like to share on the topic, so feel free to leave a comment below.