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What is Noise Cancellation?

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  • 5 min read

Earphones or headphones are an important part of most people’s daily lives. Whether on your daily commute or working out of a coffee shop, they allow you to listen to music or whatever it is you want without having to blast everyone in the vicinity with your content.

Noise-cancelling earphones are also especially helpful as they block out outside noise and usually give the user a better listening experience. But how does noise cancelling work, and do you need to spend extra money on earphones with the feature?

This article discusses noise-cancelling earphones/headphones, how they work, and whether or not you need the feature.

Also Read: 10 best noise-cancelling earbuds and headphones


How does active noise cancellation work?

An Active Noise Cancellation system (ANC) uses mics present around the earphones/headphones uses additional mics to capture and reduce unwanted background noise.

The system uses these mics to ‘listen’ to the sounds outside and inside the earphone. It consists of an ANC chipset that inverts the soundwaves, and a speaker available within the earphone cancels the outside sound by use of neutralising soundwaves.

To achieve noise cancellation, we can proceed with the use of an ANC chipset in either form:

  • As a feed-forward ANC system with a microphone placed on the outside of the earphone.
  • As a feedback ANC system with a microphone placed inside the earphone.
  • As a hybrid ANC system, a combination of a feed-forward and a feed-back ANC system.

It’s important to note that noise-cancelling devices won’t automatically cut out all sound in your surroundings. They work with only a specific set of frequencies, especially lower ones like the rumbling on an airplane or the subway.

ANC earphones/headphones come with external mics that pick up ambient sound.

Other sounds, like a regular conversation in a cafe or other higher frequency sounds, will still make it inside your ears, but the music or audio you’re listening to will keep it out, cutting out any other ambient noise you might listen to otherwise.

Another thing to remember regarding in-ear earphones is that the effectiveness of the ANC system largely depends on how well the earbuds fit in your ears, how deep they sit and how good the overall fit is in your specific ears. That’s why it’s best to experiment with ear tips of different shapes and sizes to find the perfect fit.

The additional mics on your ANC headphones are also helpful in the transparency mode that pretty much all such headphones offer.

Also read: Top 7 durable headphones


Types of Noise Cancellation

There may be more than one way your noise-cancelling headphones may work. You can choose the setting, mode or cancellation type that suits your comfort.

  • Passive Noise Cancellation is available in over-ear headphones and in-ear earphones, where the earbud is responsible for keeping the surrounding noise out.
  • Active Noise Cancellation uses microphones and speakers to lessen background and surrounding noises. It is the most known type and is frequently used in over-ear headphones. True wireless in-ear earphones actively use this technology due to its small size and efficient battery life.
  • Adaptive Active Noise Cancellation allows automatic adjustment to your surroundings. It is a sophisticated version of ANC where the noise-cancelling levels adapt digitally to the surroundings. 
  • Adjustable Active Noise Cancellation permits manual adjustment of noise cancellation levels, thus allowing you to hear some background noise. It gives total control to humans.
  • Transparency Mode allows you to tune back into the world without turning off the music or taking out your earphones.
  • Adjustable Transparency Mode allows you to adjust the background noise that passes through your headpiece without switching off the music. 
  • Adjustable Own Voice allows you to control your voice during conference calls using ANC.

Also read: Top 7 noise-cancelling earbuds


Why is noise cancellation needed?

In most cases, outside or ambient sound will leak into your ears if you’re out and about. While closed-back headphones or in-ear earphones do a decent job of keeping ambient sound away, they can still fall short, depending on how loud your surroundings are.

Noise cancellation helps by keeping most low-end frequencies out, which can distort your audio. They also help keep the volume of the audio you’re listening to lower as you don’t necessarily have to blast it louder than the ambient noise coming in from your surroundings.

Finally, be aware of your surroundings if you wear ANC earphones/headphones in public. While you may gain a new appreciation for how good the ANC on your headphones is, you’ll also learn the hard way that getting hit by moving traffic isn’t a very good experience.

(With inputs from Prachi Shah)

Also read: Bluetooth codecs: Everything you need to know

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