Active noise control is a technical method that adopts electronic technology, signal processing technology and acoustic principles. It artificially generates sound waves with equal amplitude and opposite phase to the noise to be eliminated. The superposition and interference of the two sound waves reduce or eliminate noise in specific areas. Based on the acoustic interference principle, the core mechanism is that two sound waves with the same frequency, opposite phases and similar amplitudes cancel each other out to achieve noise reduction.

For instance, in an enclosed space with low-frequency noise, the active noise control system first collects noise signals through sensors such as microphones. After signal analysis and processing, the system drives speakers to emit anti-phase sound waves consistent with the original noise. The superposition of the two groups of sound waves attenuates the noise intensity in the target area and creates a relatively quiet acoustic environment.