Sound reaches us as audio waves, generated by air vibrations. These vibrations push air particles, and our brains interpret this movement as sound. Active noise cancellation operates through a process called phase inversion, creating a sound wave that matches the original in frequency and wavelength but is phase-opposite. The interaction between these two waves effectively nulifies each other, ideally producing silence.
This is an ideal scenario because active noise cancellation demands continuous and precise computation to craft a sound wave that perfectly negates the unwanted noise. Modern headphones and earbuds incorporate built-in microphones to continuously detect surrounding ambient sounds. These devices then process this data and inject a counteracting sound wave, producing what’s effectively known as anti-noise, directly into your ears when using ANC-equipped headphones.