What is Active Noise Cancelling (ANC) in Earbuds?

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Have you ever been beaten up because your mom was calling out to you and you couldn’t hear her because of your brand new ‘active noise cancelling earbuds?’

Congrats if you’ve already gotten your hands on it. It’s a blessing and probably a curse if your mom’s around.

Active noise cancellation is basically a method of reducing unwanted background sounds to provide a better and more cohesive listening experience.

These earbuds have proven to be the perfect companion when you’re commuting through busy streets or metros. They cancel out the unwanted noise peeping into your ears while listening to your favourite podcasts.

Who’s Behind Active Noise Cancelling Tech?

Who’s Behind Active Noise Cancelling Tech?

You must have heard of Amar Bose, an electrical engineer who took a flight from Zurich to Boston. It was not the only flight he took but a fateful one.

During the flight, he was annoyed by the sound of the jet and set out to get a solution.

Spending a million dollars and several years committed to research, he finally came up with the idea in the year 1978 and with a working prototype in 1986.

The prototype was specially made for airline pilots, the military, and business-class customers. In the years following, it became available to regular people too.

Let us assume Amar Bose was born in this generation; would he have found a solution that would revolutionise headphones forever? Instead, he would’ve bought his next business class plane ticket and forgotten about the annoying jet engine, thinking, ‘It’s not his responsibility.’

How do Active Noise Cancelling Earbuds Work?

How do Active Noise Cancelling Earbuds Work?
Image Source: gonoise.com

While you might assume that you’re the only one listening, let me tell you that your headphones are also listening because that’s how they cancel out the noise.

Remember when you read about sound waves? That’s how it works.

Sound travels through the air in the form of sound waves. Each sound wave is different from the other wave. These waves consist of valleys and peaks.

You can have a glimpse of it on your phone. Go to the ‘recorder’ app and try recording your voice. As you speak, you’ll notice some sort of sound waves forming while you’re talking.

Although this is not the actual sound wave, it’s just an instance to tell you how it works.

1. Constructive Interference

The waves are regular when you’re listening to a song on your headphones. When there is construction going on in the street you’re passing by, the sound waves of the construction noise and the song you’re listening to are different and form a constructive interference. 

Constructive Interference basically amplifies the sound to make the overall combination louder. Nope, this does not cancel out the unwanted noise. Destructive Interference does.

2. Destructive Interference

When the built-in mic on your earbuds detects a sound wave, the microphone creates a sound wave (waveform) which is totally opposite. So, for every valley, there is a peak, and for every peak, there is a valley. 

This way, the waves cancel each other out, cancelling out the noise and giving you blissful silence. This is called destructive Interference.

However, you may also have observed that only some of the voices are cancelled. That’s because active noise cancellation earbuds work their best in places with consistent noise. 

But what worked before Active Noise Cancelling? It was Passive noise isolation, or it is also known as passive noise cancelling. 

What is Passive Noise Isolation?

What is Passive Noise Isolation?

Passive isolation is a term used in headphones to block out external noise or sound leaking. It blocks out external noises with the help of ear tips which creates a seal inside the ear.

It is basically moulded to the shape of your ears to prevent ambient noise from entering your ears. This feature can also be found in headphones with large ear cups that block off all external noise.

Unlike ANC headphones, it does not require you to charge them. Instead, it blocks noises just naturally by fitting inside your ears. 

Active noise cancelling and passive isolation are quite similar, with an even similar goal to let you enjoy uninterrupted music.

Which is Better? Active Noise Cancellation or Passive Noise Cancellation?

When going for ANC earbuds, you’re likely to compromise on the sound quality and battery life of the earbuds. Models that do not focus on ANC tend to focus more on the sound quality and battery life, which is an important consideration while purchasing headphones or earbuds.

ANC earbuds are likely to be pricey as most of that money is going into the ANC technology, but battery life and sound quality may not be at par with the price. So, it’s better to be aware of what you’re buying or spending your money on.

Talking about sound quality, ANC earbuds add a particular bass to the sound when you turn on the active noise cancellation mode. You might like it if you like music with bass, but the bass sometimes comes across as bloated when compressed, so this also needs to be considered.

Besides, there’ll always be something left out, whether it be passive isolation or active noise cancellation. Even the most active noise cancelling earbuds can not actively cancel these noises, car honks, screaming kids, or cows braying, since passive or active, these earbuds work better with consistent noises.

Passive noise-cancelling earbuds are cheap in comparison to active noise-cancelling earbuds.


Passive noise-cancelling and Active noise-cancelling earbuds are pretty similar to each other.

Just because the latter is modern and new does not necessarily mean it’s the best.

If I were you, I would choose earbuds with passive noise isolation, as battery life and sound quality are of utmost importance to me.

Regarding noise that can be avoided by sitting under a staircase, passive isolation earbuds do block out noise. Just because it’s not named active doesn’t mean it isn’t doing anything.

Passive Noise Isolation earbuds are a good alternative if you’re not ready to invest in Active Noise Cancellation earbuds yet.