Everyday Tech Part 5: How do noise-cancelling headphones work?
Tiny microphones hear the outside noise and the speaker plays the opposite (upside-down) wave, so the two cancel and you hear quiet.
Ever wondered how noise-cancelling headphones make a plane go silent? ✈️🎧 Here's the trick 👇
👂 LISTEN: tiny microphones on the outside of each earcup hear the noise, thousands of times a second.
🔄 FLIP: a chip makes an upside-down copy of that noise and the speaker plays it with your music.
🤫 CANCEL: noise + flipped noise add up to (almost) nothing. Silence!
🤔 Quick guess — which is harder to cancel: a plane's hum or a sudden shout? The shout! Steady low hums are easy to copy, but sudden sounds are too fast, so the soft ear cushions block most of those.
Listen, flip, cancel!
Read the voiceover (transcript)
- Loud plane? One click. Gone! How?
- Tiny microphones on the outside hear the noise, thousands of times a second.
- A chip makes an upside-down copy. Noise plus flipped noise? They cancel. Silence!
- Quick guess: plane hum, or a sudden shout? The shout is harder! The cushions block it.
- Listen, flip, cancel!
- Next: how a watch feels your pulse! Follow!
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