Active Noise Cancellation (ANC) uses built-in microphones to detect ambient sound and generates an opposing sound wave to cancel it out, reducing background noise reaching your ears.
Active Noise Cancellation works by placing microphones on the outside of headphones to capture ambient sound. The device then generates an inverse sound wave — identical in amplitude but opposite in phase — that cancels the incoming noise before it reaches your ears.
ANC is most effective against consistent low-frequency sounds such as airplane cabin noise, air conditioning hum, and train rumble. It is less effective against sudden or high-frequency sounds like human voices or keyboard clicks.
There are two main ANC implementations. Feedforward ANC places the microphone outside the ear cup and reacts quickly but less precisely. Feedback ANC places the microphone inside the ear cup and is more accurate but can cause audio artifacts. Hybrid ANC combines both approaches for the best noise reduction.
ANC quality varies significantly between products. Premium headphones reduce noise by up to 40dB, while budget options may only reduce 10 to 15dB.
ANC consumes extra battery power. Most headphones offer 20 to 30 percent less battery life when ANC is enabled.