How do noise-canceling headphones work?
Show answer & explanation
Answer: They create opposite sound waves
They create opposite sound waves ✓ — Correct! Active noise-canceling uses 'destructive interference.' Microphones detect external noise, then electronics instantly generate sound waves that are opposite in phase (peaks match with troughs). When opposite waves meet, they cancel out—silence! This works best for constant low-frequency noise like airplane hum. Sudden sounds are harder to cancel because processing takes milliseconds.
They distract ears with music — Wrong. Music distraction is not noise-canceling. Noise-canceling works even in silence mode through active cancelation—generating anti-phase sound waves. Playing music at high volume can mask noise (but damages hearing). True noise-canceling reduces noise through physics (destructive interference), not psychological distraction, protecting hearing while reducing noise.
They reduce air pressure — Wrong. Noise-canceling doesn't work by reducing air pressure. It works through acoustic physics—creating sound waves exactly opposite to incoming noise so they cancel through destructive interference. Air pressure remains normal. The 'pressure' feeling some users experience is from the noise-canceling signal itself, not actual pressure changes.