Script - How do noise-canceling headphones work?

Whether you use over the ear headphones, or the more streamlined earbuds, probably familiar with noise-canceling headphones.

They can be remarkably good at drowning out ambient sounds. Letting you listen to music or podcasts without interruption. But how do noise-canceling headphones work?

Hi I’m Caroline. If you’ve ever wondered how exactly that noise canceling technology works, listen up: we’re here to explain it.

It has to do with sound waves. Sound travels through the air and wave forms like this. Here’s the waveform for what it sounds like inside a busy café: (pause for effect) 

Now here’s the exact opposite of that sound wave. See how the peaks and valleys match up? When you play these two sounds at the same time they cancel each other out. This is known as destructive interference, and the result is you get basically no sound at all.

Noise-canceling headphones work by using a tiny microphone to pick up the ambient sound around you. See? It’s right here. As your headphones listen to the outside noise, they instantly generate a sound that has the exact opposite waveform of the noise, thus canceling out the sound before it ever reaches your ear. That way you only hear the music coming from your headphones, and very little outside noise. 

This technology is known as active noise canceling or A.N.C., and it generally works best with low frequencies, or sounds that are consistent, like the low hum of an airplane engine. And no, you can’t hear the noise-canceling sound waves being generated by your headphones, but they’re there, helping you enjoy some peace and quiet, even in a noisy world. 

Did you learn something new? Like and subscribe to our channel for more answers to your everyday tech questions