Active Noise Cancellation: What Does ANC Mean?

by Praveen Kamath March 07, 2016 4 min read

Active Noise Cancellation: What Does ANC Mean?

When is Noise Cancellation Necessary?

Unfortunately for music lovers, many types of ambient sounds can interfere with or even block out music coming from their headphones.

Technically, any headphone or earphone can provide some passive noise reduction. That's because the materials of the headphones themselves block out some sound waves. The reduction in noise is about 15 to 20 decibels (dB). But considering jet engines create 75 to 80 dB of noise inside the aircraft cabin, passive models have some serious limitations at certain situations. That's where active noise-canceling headphones can make a huge difference.

What do noise cancellation headphones consist of?


How Noise Cancellation Works

Batteries – To power the noise cancellation circuitry, such headphones come with battery.

Microphone – Noise-cancelling headphones have a microphone to pick up ambient noise (such as traffic, crowd, machinery, etc.)

Noise-Cancelling Circuitry – Electronics in the ear piece create a noise-cancelling wave that is the exact opposite of the ambient noise captured by the microphone. This wave acts like a noise eraser i.e. it cancels out the unwanted sounds that surround you without diminishing the primary playback audio.


Noise-cancelling headphones have the following drawbacks:

  • Much more expensive than regular headphones.
  • Active noise control requires a power source for the onboard electronics to work its magic, usually supplied by a USB port or a battery that must be occasionally replaced or recharged. Also, without power, some models do not even function as regular headphones.
  • The noise-cancelling circuitry may reduce audio quality and add a high-frequency hiss.
The Bottom Line?

While noise-canceling headphones do a good job distinguishing between the audio a wearer wants to hear and the background noise he or she wants to keep out, some people say that they compromise the sound quality to a small extent by muffling sounds

How's the Demand?

Despite the trade offs, some may never go back to normal headphones. That's because noise-cancelling headphones do more than reduce noise. For instance, you can even use noise-canceling headphones if you don't want to listen to music but just want to cancel out background noise.

Sony MDR-EX750NA

 What is Passive Noise Isolation?

Passive noise cancelling headphones do not offer active noise-cancelling electronics. Instead, they achieve passive noise-reduction by physically covering the ears to help block out external noise.

Most passive noise isolation headphones primarily have an in-ear design that forms an acoustic seal to help block background noise and hence allow for increased fidelity of the desired audio at lower volumes.



Many in-ear and on-ear headphones isolate you from ambient noise. Some are better than others. The idea here is to create a physical barrier between your ear and the offending sounds.

With in-ear headphones, the amount of sound they reduce is based mostly upon how good a seal you’re able to achieve. Everyone’s ears are different, and as such, in-ear headphones fit everyone differently. Finding in-ears that fit well is key, especially if you’re looking to block ambient sounds well.

In case of over-ear headphones, the noise isolation usually isn’t much, but just about enough to muffle the surrounding sound to a certain extent.

Where noise isolating headphones physically try to block ambient noise with their seal against your ear, noise cancelling ones may do that too, but furthermore they also electronically cancel the actual unwanted sound waves.

Noise cancelling headphones require batteries. They also range in quality quite a lot. The best work great, the worst barely work at all. What’s even worse is that cheap ones can actually add some noise in the form of hiss.

Noise isolating ones, at best, can muffle everything around you decently. But when it comes to cancelling out intense and much more prominent noise, they are rendered almost ineffective.


 Pros and Cons of Noise Cancelling


  • Able to reduce background noise efficiently.
  • Lets you listen to music at a lower volume.
  • Can be good for your hearing, by reducing loud noises.
  • Relatively more comfortable


  • Requires batteries. (Though, most NC headphones come with rechargeable batteries).
  • It is expensive.
  • Big differences in terms of quality - High quality noise-cancelling headphones do a good job, but low-quality ones hardly make any difference at all.


Pros and Cons of Noise Isolation
  • Can reduce background noise to some extent.
  • Are cheaper than noise cancelling headphones.
  • Doesn’t require any batteries.


  • Doesn’t reduce much noise in comparison to noise cancelling headphones.
  • Can be uncomfortable. As these headphones block noise by pressing against or over your ears, they can be uncomfortable to wear for long periods.


The takeaway here is pretty simple, it comes down to your requirement rather than just personal preference.

If you work in a studio or an orderly environment, you probably won’t need it. If however, your work enables you to travel very often, or you reside or work beside a noisy environment, this is where choosing the Active Noise Cancellation ones would make more sense.

Also if you do not prefer listening to your music on loud volumes, yet want interfering ambient noises to be nullified, choosing a Noise Cancellation headphone would be the smarter choice.

If you liked this article, you may also like: What are headphone amplifiers and do you need one?

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Praveen Kamath
Praveen Kamath

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