What is noise canceling (ANC)?

Noise canceling filters out background noise through your earbuds or headphones. There's active noise cancelling, passive noise canceling, and some manufacturers simply list noise canceling on their products. Here's a quick, simple guide to what you need to know about noise reduction.

What is ANC?

ANC (active noise cancelling) means your earbuds or headphones filter out background noise. You hear less of your surroundings and more of your music when you're listening.

So what makes ANC active?

A microphone in your earbud picks up background noise, and an opposing sound plays at that exact moment. That's what makes it active. More on how noise canceling works later.

Benefits of noise canceling

The benefit of noise canceling is that you don't hear background noise. That can be useful when traveling by train or plane, or when you want to focus on reading or studying.

It's very pleasant. When you turn on noise canceling, you really do hear a reduction in background noise. But if someone next to you starts talking, you can still hear their voice and make out the words. It's no miracle solution, but it does work.

Drawbacks of noise canceling

Does ANC have drawbacks too? Definitely. In some situations, it can even be dangerous.

Your battery drains faster

The battery doesn't last as long. As you can imagine, active noise cancelling puts your earbud's chipset to work. Sound coming in through one of the earbud's microphones has to be encoded immediately. An opposing sound then needs to be calculated, and that opposing sound has to play in your ear.

That takes a lot of energy for an earbud. It means the battery drains faster than when ANC is off. But there's a simple solution: you can just turn ANC off. Your batteries will last longer again.

Dangerous in some situations

In some situations, blocking out background noise is a very bad idea. Think of running, riding a moped or motorcycle, or driving a car. In other words, especially when you're out in traffic.

Noise canceling struggles with wind

Another problem is that the technology uses a small microphone in the earbud. And microphones don't handle wind well. We demonstrated this in this test, with recordings with and without wind.

What is passive noise canceling?

Passive noise canceling means you hear less background noise because something is in or over your ear. What? Is that all? Yes, that's all. Every earbud or pair of headphones effectively has passive noise canceling.

So if a product lists "noise canceling," read carefully to check whether it means passive noise canceling or active noise cancelling.

In our view, active noise cancelling is overrated and passive noise canceling is underrated. Put in a good pair of in-ear earbuds with passive noise canceling, and you'll immediately hear much less background noise. Turn on your music, and you won't hear any background noise at all.

What is (true) adaptive noise canceling?

Adaptive noise canceling, also called true adaptive noise canceling, theoretically goes a step beyond ANC. True adaptive noise canceling tracks the pattern of background noise over a longer period, such as 20 seconds, allowing it to produce a much more accurate opposing sound.

The difference between ANC and TANC is that active noise cancelling (ANC) assesses the sound from scratch each time to create an opposing sound, without considering the sound from the previous few seconds. Adaptive noise canceling assesses your situation more thoroughly and can adjust the level of opposing sound accordingly.

The result? In practice, TANC is better because it doesn't have to reinvent the wheel, or the opposing sound, every second. It adjusts its behavior to your situation.

How does noise canceling work?

Noise canceling in earbuds and headphones works in 3 steps:

Step 1: A microphone picks up background noise

Sound enters through a small microphone in the earbud or headphones. This is how background noise is picked up.

Earbuds with ANC on a plane

What many people don't know is that background noise is picked up by a separate microphone. That means the earbud or headphones have:

• 1 microphone for noise canceling
• 1 microphone for calls or online meetings
• And sometimes 1 microphone for ENC
  (That's something different: environmental noise canceling for calls)

Step 2: Background noise is encoded or digitized

The mic has now picked up the sound. The chipset in the earbuds or headphones digitizes it very quickly. That's the same process that happens with a microphone.

The sound is converted into code. This happens in the chipset of the earbuds or headphones. But that's not all!

Almost at the same moment, the earbud or headphones calculate an opposing sound. This opposing sound is meant to neutralize the background noise.

Step 3: The opposing sound plays in your ear

The final step in making noise canceling work is playing the opposing sound through the earbud's speakers. This is the step that actually neutralizes the background noise.

And there you have it! Those are the three steps needed to make ANC work.

Does noise canceling work without music?

Noise canceling also works without music. Just don't expect miracles. Still, if you're on a train wearing your earbuds or headphones without music playing, turning on ANC does reduce the sound of the moving train.

On the other hand, is that really what you want? A quiet opposing sound is still playing in your ear to stop you from hearing the noise. You could also wear in-ear hearing protection to reduce background noise. That would be passive noise canceling.

Noise canceling while sleeping

You can also use noise canceling while sleeping. But again, I'd ask you: is that really what you want? Consider that a Bluetooth device will be working close to your head for 8 hours.

You'd be much better off buying ear protection for sleeping. It seals your ears very effectively without active noise cancelling.

Noise canceling as hearing protection

In some jobs, hearing protection is mandatory. That has less to do with the job itself and more to do with the number of decibels you're exposed to at work.

At 85dB and above, you must use hearing protection, but only if that noise is constant.

So are noise-canceling headphones good enough? The short answer is no. Hearing protection must meet the EN-352 standard. This standard requires headphones to actually reduce noise below a certain dB level. NEN has established this standard.

For hearing protection, you're much better off buying earmuffs specifically designed for that purpose. You can also get custom-molded in-ear hearing protection.

Others also viewed:

• Browse all our blogs about wireless earbuds
• These are the best earbuds under €50
• These are the earbuds with the best microphone
• Also check out the 3 best earbuds for running
• Also check out our hands-on with the Eardopes B6 pro.