Noise cancelling headphones are a popular choice for people who want to listen to music without the sound of other people or animals. However, there are a few things you should know about noise cancelling headphones before you buy them. First, noise cancelling headphones are not always effective at cancelling out all sound. In fact, some sounds may still be heard even with the headphones on. This is because the ear cups have a small speaker inside them that amplifies sound and sends it back to your ears. Second, if you have a large head or ears, some sounds may still be heard even with the headphones on. This is because the ear cups have a small opening in them that allows sound to enter and exit your ears easily.
Over the last decade, noise-canceling headphones have become more common, more affordable, and more effective. But as headphones become better at filtering out external sounds, more and more people complain that they cause ear pain, headaches, and a feeling of inner-ear “pressure.” These complaints date back further than 2009, so why hasn’t this issue been resolved yet? Well, first, we have to understand how noise-canceling headphones work.
ANC Headphones Listen to External Noises and Cancel Them Out
Contrary to popular belief, active noise canceling (or ANC) headphones don’t block out noise by physically shielding your ear from external sound waves. They aren’t like fluffy shooter’s earmuffs; they’re just small pieces of plastic. So how do ANC headphones cancel out sound?
Like light, sound travels through the air in “waves.” And just as different frequencies of light are recognized as different colors, different frequencies of sound are perceived as different pitches.
The thing is, sound is a “pressure wave.” Unlike light, sound is capable of moving through solid objects, like walls, water, and a plastic pair of headphones. Low-frequency sound waves are especially good at moving through solid objects (think of a bass drum), but high-frequency sounds (like the nasty sound of a CRT TV) aren’t that great at moving through objects.
So, ANC headphones aim to eliminate low-frequency sounds. They do this by monitoring your noise environment with a built-in microphone, identifying the frequencies of said noises, and blasting your ears with an anti-noise wave that cancels out the unwanted external sounds.
This sounds complicated, but it’s easy to understand. An anti-noise wave is basically a mirror version of the sound that your headphones are trying to eliminate. It’s the same frequency (pitch) of the unwanted noise, but with a reversed polarity (again, a mirror version). When two sounds with opposite polarities meet one another, they’re both canceled out. It’s weird, but that’s science.
Why Do My Ears Feel “Pressure” On an Airplane?
Okay, so ANC headphones cancel noise by pumping an anti-noise wave into your ears. But why do they hurt people’s ears and cause headaches?
Most people describe the feeling of ANC headphones as a sort of “pressure” on the ears, like the changes in atmospheric pressure from ascending in an airplane or diving deep into the ocean. So, it’s important to understand how air pressure works (and its relationship with sound perception) before we try to figure out why ANC headphones put “pressure” on your ears.
Atmospheric pressure (also called air pressure and barometric pressure) is the force extended on a surface by its atmosphere. Gravity from our Earth is constantly pulling atmosphere down, so the air in low altitude climates (the bottom of the ocean) is denser than high altitude climates (a mountaintop or an airplane in flight).
Now, atmospheric density isn’t what causes painful pressure in your ears. That feeling of “pressure” is caused the difference between the air pressure of your inner ears and the air pressure of your environment. If you’re at a high altitude, then the air in your ears wants to escape. If you’re at a low altitude and under a ton of pressure, your inner ears need more air so that they won’t collapse. When you “pop” your ears, you’re just equalizing your in-ear air pressure with the air pressure of your environment, and the feeling of “pressure” goes away.
ANC Headphones Don’t Put “Pressure” On Your Ears
But your brain doesn’t just rely on ear pain and headaches to determine when there’s a change in atmospheric pressure. It also looks at how much your middle ear vibrates.
When you first go up in an airplane, your ear has more air density than your environment. As a result, your inner ear is a bit like a balloon, it’s under a lot of pressure, and it doesn’t vibrate much. This lack of vibration results in decreased low-frequency hearing, so your brain tends to operate under the assumption that a loss in low-frequency hearing indicates a change in atmospheric pressure. (This is also the reason why you can hear better in a plane after popping your ears.)
Remember how ANC headphones aim to cancel out low-frequency ambient noises, like the sound of an engine? Sometimes, this can trick your brain into perceiving a change in air pressure.
Of course, your brain isn’t actually receiving any feelings of pain or discomfort. So, it starts to emulate those feelings to encourage you to pop your ears. Since popping your ears doesn’t resolve the lack of low-frequency ambient sound, the sense of pain and pressure can increase until you take off your ANC headphones.
Some People Aren’t Built for ANC Headphones
Some people don’t experience any discomfort while using ANC headphones. Others get used to the feeling over time, but some people can’t get past the sense of “pressure” that ANC headphones can cause.
So, if your brand new pair of ANC headphones are causing a feeling of “pressure,” ear pain, jaw pain, and headaches, then your options for dealing with the situation are minimal. You could use the headphones for about 15 minutes and hope that your brain adjusts, or you could return the headphones and reinvest your money into sound isolating earbuds or some shooting earmuffs to put over put over a regular pair of earbuds.
Just keep in mind that, even if a feeling of pain is “made up” by your brain, that doesn’t make the pain any less real. If your brain refuses to adjust to a pair of ANC headphones, then you should leave it at that. There’s no reason to torture yourself (or potentially hurt yourself) just for the sake of blocking out ambient noise while you listen to podcasts.
Sources: The Friedel Chronicles/Medium, Wikipedia, Starkey
