ANC (Active Noise Cancellation) Explained

Noise-isolating earbuds work just like earplugs that physically block out the noises, while noise cancelling earbuds technically and physically cancel out the ambient noises.

Take a look at Sony MDRNC13 and SONY XBA-4 seem to look almost the same as other earbuds except that the inside the Sony MDRNC13 housing and in-line compartment there are a circuitry to receive and invert wave from microphones which pick up the ambient sounds.

The inverted wave is created from earbud speakers that will cancel out the wave from environment–we call it “destructive interference”, resulting in users hearing less of the outside world.

This is called ” Active Noise Cancelling (ANC) process. Sony MDRNC13 earbuds also have the additional battery pack in the compartment to power ANC function.

Sony noise cancelling earbuds
Sony MDR-NC13 with battery compartment to power the ANC circuitry
SONY XBA-4 with Passive noise cancelling or noise-isolating feature

Find out the noise-cancelling and noise-isolating.

ANC earbuds (in ear headphones) work effectively on the sounds that constantly produced like air-conditioners or jet engines.

Can noise-cancelling earbuds cancel out almost incoming ambient sound say 100%?

Literally they can’t since it relies on the working ranges of the noise-cancelling components, which is the range of frequencies that the ANC circuitry can generate.

It can only work perfectly with certain frequency ranges from car or airplane engines, air conditioners but human voice like baby crying, shouting are not reduced significanlty.

Finally, the circuitry will create a white noise, you will barely hear the background noise, and the good ANC earbuds will not produce much “hiss”.

Not all noise-cancelling earbuds are comfortable to wear, effectively reduce noise and have long battery life. It’s just great with a good set that you can enjoy music even on the long flight without disturbing from noise of jet engine while still feel comfortably.

Additionally, the noise-cancelling feature requires battery to run its function, which can be internal or removable and the longer battery life the better, and the Bose QC 20 offers the longest up to 16 hour with integrated battery. However, the battery box can be weighty that may tug earbuds out of ears.

AKG K391 NC has the integrated battery that can last for up to 40 hours for streaming music with ANC function switched on.


Earbuds without the function noise-cancelling will be noise-isolating. The sound, which can be screaming kids, dogs barking, yelling just about all sounds, is primarily isolated by earbud tips that come with different sizes. The advantage of noise-isolation earbuds is that they don’t require a battery. So choose a pair of earbud tips you feel the most comfortable and and give best fit to your ears. Etymotic ER4PT ($299) with triple flange eartips is very good at noise-isolating, or RHA MA-750-enhanced bass earbuds was designed to give great fit to users, indeed they both sound good. 

Is it really necessary to get a noise-cancelling earbuds? it depends where do you use them. At the same price, the noise-isolating earbuds are better ANC in term of sound quality. Moreover, the noise cancelling function if working well, is more comfortable because we do not have to wear earbuds too tight to hear clear sound like noise-isolating earbuds. 

Technology gives us a lot of awesome things, but it can also add up the problems, like the noise-cancelling if they malfunction or it was not cared much by the manufacturer ( they add this functions to advertise the earbuds on the market) you coud hear the intense background noise. The ANC headphones also produces hiss noise–white noise caused by the electrical circuit. 

If you travel a lot on train or flight, this clever sound cancelling technology could make you happier and more relaxed audio experience.

One Response

  1. Geoffp February 18, 2015

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