How Do Noise Cancelling Headphones Work?

How Do Noise Cancelling Headphones Work?

If the idea of tuning out the world and getting lost in your favorite music sounds appealing, you’ve probably considered noise-cancelling headphones.

There are actually two types of noise-cancelling headphones: active and passive. One uses special circuitry to reduce ambient noise that would otherwise interrupt your music. The other forms a tight seal inside or around your ear to isolate the listener.

Let's take a closer look at active and passive noise-cancelling headphones. We'll also dive into the benefits of these headphones and consider some of the best noise-cancelling models available today.

How active noise-cancelling headphones work

Active noise-cancelling refers to special circuitry inside headphones that "tricks" your ears into thinking there isn't any sound around you:

  • Tiny microphones embedded within the headphones “listen” to ambient sounds in the outside world.
  • Electronics inside the headphones generate a sound wave that is 180° out of phase with the sounds around you, literally canceling them out.
  • You enjoy an island of near silence, save for whatever music you decide to play through the headphones.

Because of the extra electronics required for active noise cancelling, these headphones tend to go through batteries pretty quickly. If you opt for a pair, it’s a good idea to carry some extra batteries. If you’re using a model that includes a charging cable, you should keep that handy, too.

How Noise-Cancelling Headphones Work

How passive noise-cancelling headphones work

Let’s be clear about passive noise-cancelling: There’s nothing happening inside these headphones that “cancels” ambient noise. You won’t find any of the special electronics that live inside active noise-cancelling headphones. For this reason, passive noise-cancelling models are also called “noise-isolating” headphones.

Naming conventions aside, you’ll find these headphones as either:

  1. Closed-back, over-ear headphones that separate you from ambient noise, or
  2. In-ear headphones that form a tight seal to prevent sound from "getting in" and interrupting your music.

The lack of noise-cancelling circuitry doesn’t mean passive noise-cancelling headphones are inferior to their active counterparts! High-quality models do a fantastic job of isolating the listener, even when there's no special electronic wizardry at work.

Benefits of noise-cancelling headphones

Whether you choose an active or passive model, noise-cancelling headphones help create an environment that's free from ambient noise and distractions – something that's almost impossible to achieve under normal conditions.

After all, if you’re home alone, you can hear your refrigerator humming or your air conditioner turning on and off. Even at the library, there’s an ambient rustle of others turning pages and pulling books from shelves.

And so on. High quality noise-cancelling headphones erase virtually all of those noises. You’re left with a state of sonic solitude As a result, you can engage with your music – and only your music – without sacrificing any aspect of the listening experience.

Aside from the joys of immersive listening, here’s another reason to consider noise-cancelling headphones: saving your hearing. According to audiologists, listening through headphones at over 80 decibels can increase the risk of hearing loss.

And with conventional headphones, you might be cranking the volume more often than you think.

For instance, have you ever struggled to hear your tunes over the commotion inside a busy airport? Or maybe when traffic is whizzing by? It’s easy to turn up the volume in an attempt to drown out ambient sounds, and you might even do it subconsciously. At best, it’s a little annoying to have to listen to music at high volumes. At worst, you could damage your hearing.

To be sure, most in-ear headphones do a pretty good job of reducing ambient noise. A reduction of 25 to 30 decibels is typical. But if you’re always tapping the “plus” button to hear your music in noisy environments, noise-cancelling headphones might give your ears a much-needed break.

If you value interruption-free listening, noise-cancelling headphones are definitely worth it.

Noise-cancelling headphones are perfect for anyone who wants to check out for a while and spend some quality alone time with their favorite tunes. That’s most of us, so it makes sense that so many people rave about noise-cancelling and noise-isolating headphones.

The next time you find yourself in a noisy environment, need to focus, or just want an excuse not to answer the phone, slip on a pair of noise-cancelling headphones and tap “play.” You won’t regret setting aside the time for yourself.

The solitude might even be therapeutic.

Recommended noise-cancelling headphones

Now that we've explored the "how" and "why" of noise cancelling, let's take a look at some great noise-cancelling headphones. If you find something you like, we hope you will purchase them here, at

Sony WH-1000XM4 Wireless Over-Ear Headphone

For active noise-cancelling, we recommend the Sony WH-1000XM4, which is an over-ear headphone model. Fully-loaded with the coolest tech, the Sony XM4 takes you deeper into silence and the music with Sony’s industry-leading Noise Cancelling Technology and smart listening features that adjust to you and your surroundings. 

In our tests, active mode really came in handy when we were walking along a busy street with sirens, honking cars, and the sounds of people talking all around us. Overall, the active noise cancellation in the XM4 will do the best job of canceling out higher frequency noise in your environment.

Even when there wasn’t much ambient noise, we turned active noise-cancelling off and kept on listening to music with Sony’s premium Liquid Crystal Polymer diaphragms. The WH-1000XM4 delivers a full range of frequencies up to 40 kHz for exceptional sound quality that’s perfect for handling heavy beats. 


  1. Sony WH-1000XM4 Wireless Over-Ear Headphones, side view Sony WH-1000XM4 Wireless Over-Ear Headphones

Bowers and Wilkins PX7 Wireless Over-Ear Headphones

If you need great noise-cancelling performance, but you also want good isolation without any special circuitry, the Bowers & Wilkins PX7 gets our highest recommendation. The pressure-relieving foam pads around the earcups are larger than most noise-cancelling over-ear headphones — they cover more surface area around the ears that locks sound in and blocks noise out. The earpads provide an isolating listening experience that few other models in passive mode can match.

With the PX7, B&W borrows heavily from the technology used inside their studio speakers. PX7s are high-performance-grade headphones crafted with a special carbon fiber composite material that’s extremely flexible and lightweight. Carbon fiber has anti-resonance properties that have acoustic advantages as well, so unlike cheap plastics use in most noise-cancelling headphones, the superior build quality doesn’t interfere with the headphone’s great sound. 

The original edition B&W PX7 headphones are available in Space Gray and Silver.  There's also a new Carbon Edition that takes the high-performance look to a whole new level. 

In our tests, active mode really came in handy during phone calls when we were walking and talking in a crowded street. Lower-frequencies like the low-end “hum” of a car or the sound of a train passing are were reduced the best. Overall, the active noise cancellation in the PX7 will do the best job of canceling out lower frequencies in your environment.


Sony WF-1000XM3 Noise-Cancelling Truly Wireless In-Ear Headphones

Generally speaking, in-ear headphones have a smaller fitting design that will provide the best seal with great isolation. These in-ear headphones excel at doing both of these things, but they also fit inside your ear canal without falling out – not like the earbuds that came with your last smartphone. This alone makes the Sony WF-1000XM3 a perfect match for anyone with an active lifestyle and who wants the best-fitting universal earphones for the money.

These come fully-loaded with Sony’s industry-leading Noise Cancelling Technology and many cool features from the Sony WH-1000XM4 — but in a smaller version, you can carry around in your pocket. 

They also have a new premium digital-to-analog converter with 24-bit audio signal processing and good amplification. In our tests, these are simply the best sounding wireless earbuds on the market today.



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