How did someone think to invent this?!? It’s wild to me. In this video we’re breaking down how do noise cancelling headphones actually cancel sound? Here’s what’s happening: Most ambient noise like the hum of an airplane engine or a train… is low-frequency, predictable sound, usually under 1000 Hz. Noise-canceling headphones have outward-facing microphones that constantly sample these incoming pressure waves. Then, a digital signal processor (or DSP) analyzes that waveform and calculates its inverse… a sound wave that’s equal in amplitude but 180 degrees out of phase. This inverse signal is played through the speakers inside your earcups at the exact same time the original noise hits your ears. The two waves interfere destructively, meaning they cancel each other out at every point. That’s destructive interference. All of this happens in under a millisecond. The DSP needs to process, invert, and play back the signal before your brain can even register the noise. #tech #techexplai...