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What is ANC or active noise cancellation?

What is ANC or active noise cancellation?
What is ANC or active noise cancellation?

What is ANC? ANC stands for active noise cancellation. It is a technology that is used to reduce the environmental noise leaking into the earbuds, thus giving a good audio experience and keeping you isolated from noise. Let’s see more about ANC and how it works. 

What is ANC or Active Noise Cancellation?

As we have said, ANC stands for active noise cancellation. It is also called active noise control. It is ‘active’ because the earbuds or headphones, wherever implemented, require electronic hardware, software and electricity to function well. Before diving into how the ANC works, let’s see some history.


Mr Paul Lueg patented the first-ever noise reduction technology in 1936. Then the advancement begins, according to Wikipedia, that can cancel up to 20 decibels of noise. But, it is only between 50 Hz and 500 Hz. The advancements were ongoing, and in 1989, Bose introduced noise-cancellation earphones for aviation, and from there, there was no turning back. Now, Bose and Sony are the top players in active noise cancellation or ANC.

How does it work?

pictorial representation of how ANC works.
image courtesy: Wikipedia

It works on wave cancellation technology. Imagine you’re wearing a headphone or a pair of earbuds. The only way noise can get inside the ear canal is through the gap between the ear canal and the ear tip. In the case of headphones, the gap between the earpads and the skin. Even if the ear canals are sealed well, noise still makes its way into it through the tiny gap and the ear tip/earpad itself. Remember, sound can travel through solids.

Now, the earbuds and earphones that are equipped with ANC have one or multiple mics around the earphones/headphones. Those mics capture noise from the environment. This noise is sent to the microprocessor or DSP. 

The dsp inverts the phase (angle) of the sound and sends it to the driver of the earphones. The driver produces the noise in the ear canal.

This phase inverted noise meets the noise that slipped into the ear canal through the gap. Since both the sound waves are out of phase, they cancel each other due to destructive interference. The result is a noise-free sound that hits the eardrum. 

There cannot be 100% noise cancellation because of so many factors. The main element is the speed of sound. There will obviously be a difference between the speed of the direct sound wave and the sound wave captured by the microphone, which will be sent to DSP and then to the driver because any sound through electronic means will produce a slight latency. This makes some of the noise still creep into the eardrum.

Why should you use ANC?

You should use ANC not only to keep you away from the noise on streets and on an aeroplane, but you should also use it to listen to the music how it should be.

Usually, the music has low-level details that have very low volume. Symphonies are a perfect example. If you’re listening to songs with low-level details and if there is noise, it can prevent you from hearing those minute sounds. This is where ANC helps you the most.

It is quite a good feeling to listen to music in silence. Other uses are to reduce the engine sound while travelling on an aeroplane, bus or train. 

Another important usage is that the ANC indirectly helps keep the music sound low. More the noise more you crank up the volume. The more you crank up the volume and more the chances of getting deafness. With ANC on, the noises are kept away, and you don’t need to crank up the volume to indulge in music.

Is ANC effective?

ANC is very effective. Even the cheapest ANC earbuds can reduce up to 25 DB of sound, which is excellent. You can clearly tell the difference as the difference is significant. The icing on the cake is, in many cases, with ANC-enabled earbuds, the noise reduction is comparatively more than the over-the-ear earphones.

Passive noise control

Since we are discussing ANC or active noise control, there arises a question, if there is an active noise control, then is there a passive noise control? The answer is yes; there is passive noise control. Passive noise control is nothing but the effectiveness of ear pads and ear tips to keep the noise from slipping into the ear canal through the available gaps. For a good ANC, there should exist reasonable Passive noise control too.

What are the earbuds that have ANC?

Image of a boAT audio 413 ANC case and earphones
boAt Airdopes 413 ANC

There are many earbuds in the market that do ANC, and the most popular ones are QuietComfort earbuds II and Sony WF-1000XM3. You get boAt audio 413 ANC and Boult audio Omega earbuds at a lower price. On the headphone side of things, Sony WH-1000XM5 and Bose Qc 45 are the best.

What is ENC?

When talking about noise cancellation, we often come across a term similar to ANC, which is ENC. 

Enc stands for environmental noise cancellation. This is available in cheaper and more expensive products. boAt audio advertises its ENC as ENx

So, what is ENC?

ENC stands for environmental noise cancellation. It is a technology that gives clear voice calls to the earbuds.

Since the mics on the earbuds are recessed, and no way closer to the mouth, earbuds have a hard time capturing human voices during a phone call. Along with the human voice, it captures the noise too. ENC cancels out the noise so that the person on the other end of the line can hear you clearly.

How does it work?

It works similarly to ANC. There are mics on the earbuds to capture vocals. It also captures noise. This noise is digitally processed, phase inverted and mixed with the primary signal. This way, destructive interference happens, and as a result, we get clear vocals.

You can read the dedicated article on what is ENC and how does it work?


So, what is ANC? ANC stands for active noise cancellation, and this technology cancels the noise entering into the earbuds; therefore, it gives you near silence, and the music you will hear has good sound quality. I hope you have understood what ANC is and its related terms. Thanks for reading.


What is ANC?

ANC stands for Active Noise Cancellation. This technology cancels external noise by DSP and thus giving you a silent experience and/or good sound quality.

What is ANC for headphones?

ANC for headphones is Active noise cancellation technology embedded in headphones like Bose quiet comfort 45

What is the meaning of ANC?

ANC stands for Active noise cancellation, and it is a technology to reduce noise and improves sound fidelity on earbuds and headphones.

What are ANC AirPods?

NC Airpods are the AirPods with ANC. Not all Airpods have ANC. Only Airpods Pro and its second generation have ANC.

Is ANC necessary?

ANC is not a must-have, especially when you have a silent place to listen to music. But having ANC on your headphones and earbuds will ensure you get silent and noise-free music even at crowded locations like aeroplanes, trains, coffee shops etc.

Is 25 db ANC good?

25 DB ANC is very good. I have an earbud that does 25 DB ANC, and I couldn’t be happier with it.

Is ANC good for health?

Yes, ANC is good for health. Since ANC reduces noise and also indirectly reduces listening to music at high volumes, ANC is good for your hearing.

Does ANC cause ear pain?

No, ANC does not cause ear pain.

Does ANC have side effects?

ENC does not have any side effects as far as I know.

Does ANC affect hearing?

No, ANC does not affect hearing.

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