Active Noise Cancellation is audio processing that reduces unwanted ambient sound by generating an opposite phase signal through the device speakers. In headphones and earbuds, microphones sample the outside environment, firmware or a DSP calculates a canceling waveform, and the system mixes that signal with the audio path. ANC works best for steady low-frequency noise such as engine hum, fan noise, or air conditioning.
In cyber security, ANC matters because modern audio devices are small computers with microphones, radios, and firmware that shape what the user hears and captures. Good ANC can improve call quality, reduce background distraction, and make voice input more reliable. But it is not a security control: it does not verify who is speaking or stop audio spoofing. Attackers may still use replayed, synthetic, or loud injected sounds to influence users or speech systems, while defenders should remember that firmware and app settings can change ANC behavior and privacy expectations.