noisecancelling

NoiseCancelling refers to technologies designed to reduce unwanted ambient sounds in an environment or in the listener's ears. It includes passive approaches that physically block sound with enclosures or materials, and active noise control, which uses electronic processing to cancel sound. The term is most closely associated with headphones and headsets, but applies to other devices and architectural applications as well.

Active noise cancellation (ANC) works by detecting ambient noise with microphones, generating an anti-noise signal with a digital processor, and delivering it through speakers to destructively interfere with the unwanted sound. ANC systems may be classified as feedforward (measuring external noise with microphones outside the ear), feedback (inside-ear microphones), or hybrid, combining both approaches.

Applications include consumer headphones and earbuds, aviation and military headsets, automotive cabin noise control, and industrial or architectural settings such as speech privacy in offices or quiet HVAC enclosures.

Performance and limitations: ANC is most effective at steady, low-frequency noises such as engine rumble or air conditioning. It is less effective for sudden or high-frequency sounds, and it requires power and proper fit. Some users may perceive faint tonal artifacts or reduced audio fidelity if not well tuned.

History: The idea of active noise control emerged in the mid-20th century, with early demonstrations in aviation headsets and industrial contexts. Commercial ANC began appearing in specialized products in the late 20th century and gained broad consumer adoption in the 2010s.