Active Noise Cancellation

A technique that reduces unwanted ambient sound by using microphones to capture incoming noise and electronically generating an inverted (anti-phase) audio signal that destructively interferes with it, lowering the perceived noise reaching the listener's ear. ANC is the core technology in noise-cancelling headphones and earbuds (AirPods Pro, Bose, Sony) and is most effective for steady, low-frequency sounds like aircraft cabin noise. For accessibility, ANC is widely used by autistic, ADHD, and noise-sensitive users to manage sensory overload, but conventional ANC suppresses the environment uniformly and so trades comfort for situational awareness. Newer 'transparency' or 'adaptive' modes selectively pass through some ambient sound, and emerging 'semantic hearing' systems aim to suppress only user-specified categories of sound rather than the entire soundscape.