How do noise-cancelling headphones actually block out sound?”

Question

I’ve always been curious about how noise-cancelling headphones work. It feels like magic that they can block out background noise while still letting you hear music or podcasts clearly. Can someone explain in simple terms how they cancel out unwanted sounds?

In: Technology

Answer 1

They have microphones on the outside that pick up the external noise pattern and then play back the exact opposite noise pattern on top of the actual headphone audio. Because sound is just waves of compressed and expanded air molecules, the opposing sounds cancel each other out.