the.com/noise cancellation
Science fights sound with its own mirror image, and silence wins.
means A technology that cancels unwanted sound by generating an inverted sound wave that destructively interferes with it, leaving relative quiet behind.
from 'Noise' traces back to Latin nausea (seasickness, queasy disgust) by way of Old French — a word for sound that started as a word for sickness. 'Cancel' comes from Latin cancellare, 'to cross out,' originally meaning to mark something with crossed lines, like a lattice (cancelli, 'latticework,' also the root of 'chancel' and 'chancellor'). The technology itself is 20th-century: engineers realized that if you record a sound wave and play back its exact mirror image, the peaks and troughs cancel out — physics doing literally what the word promises, crossing the noise out.
- the trick
- generates inverted sound wave to cancel the original
- blind spot
- struggles with sudden sounds like voices or clinks
- side effect
- some feel mild ear pressure or dizziness
- origin
- invented 1930s to quiet aircraft cockpit noise