How do noise-cancelling headphones work?

It’s one of the most satisfying bits of modern magic: you flip a switch on your headphones, and the roar of a jet engine or the drone of a busy office simply vanishes into a bubble of quiet. But how is it possible to erase a sound? How can a device add more sound to the air to create silence?

In this episode, we break down the incredible science of noise-cancelling headphones. We explore the physics of "destructive interference," where two sound waves meet and cancel each other out, and reveal how a tiny microphone, a computer chip, and a speaker work together to create a wave of "anti-sound." We'll dive into the surprising origin story of the technology, born from a frustrating airplane flight, and explain the different "flavors" of noise cancellation that make some headphones better than others. Finally, we’ll uncover why the sil ...