If you’ve spent any time researching modern consumer headphones, you’ve probably come across the concept of noise cancellation. Most consumers understand that these headphones provide more silence from their surroundings than when they’re not wearing headphones, but how does it all work?
How Noise Cancelling Headphones Work
In this guide, we explain how headphones cancel noise, how the technology works, and what role it plays in listening to music.
Active noise cancellation uses the natural laws of physics and sound to reduce noise. If your headphones were to use their microphones to read a waveform as noise, noise canceling headphones would produce a small amount of noise at the exact same amplitude and frequency as the waveform.
They played it "out of phase" (a fancy term for two sounds that are the same, but slightly earlier or later than each other). These waveforms then add and cancel each other out, like a positive number and a negative number. This process leaves you with a vacuum-like silence.