Explained: How Noise Canceling Headphones Work

2 min read

When we’re flying on a plane, riding on the train, or just surrounded by a lot of people, it can be really difficult to focus. Music helps a lot of people, but it doesn’t remove all of the noise. That’s where noise canceling headphones come in, so let’s take a closer look.

Various headphones such as the Bose QC35 (that I personally love) use noise canceling technology to get rid of the ambient noise around you to let you focus on the music. How does it actually work? That depends on the type of headphones you’re using. There are two types of noise cancellation ─ active and passive. First, let’s look at passive noise cancellation.

Passive noise cancellation is pretty simple, and it works with basically any pair of headphones. That’s because passive noise cancellation boils down to blocking external noise from entering your ear. It can work, but generally, it’s nothing impressive. Some headphones are better at this than others though.

Active noise cancellation, on the other hand, makes a much bigger impact with getting rid of ambient noise. It accomplishes this by using a microphone to detect sound that isn’t what the headphones are already outputting and uses that to create an opposing signal in the ear cup. That’s why when you turn on the headphones, you might feel a sort of “pressure” on your ears.

How effective the cancellation works depends on the pair of headphones you buy. I’ve yet to find an option that beats the Bose QC35, but we have reviewed options which are just a bit easier to stomach in terms of price. Generally speaking, a pair of headphones with active noise cancellation can block out about 70% of the ambient noise around you, but you shouldn’t expect it to block out quick, loud noises that occur near you. Of course, canceling out external noise isn’t without any downsides, as you can clearly notice some slight degradation in audio quality when noise cancellation is active.

Bose QC35 Review