How Do Noise Cancelling Headphones Work? Noise cancelling headphones use active noise control (ANC) technology to reduce or eliminate unwanted background noise. ANC works by using microphones to pick up the ambient noise around you, and then generating a sound wave that is the exact opposite of the ambient noise. This “cancellation” sound wave is then mixed with the audio signal from the headphones, and the result is a reduction or elimination of the ambient noise.
There are two main types of noise cancelling headphones:
- Passive noise cancelling headphones: These headphones use physical barriers, such as thick ear cushions or noise-isolating earbuds, to block out external noise. They do not use any electronics or active noise control technology.
- Active noise cancelling headphones: These headphones use microphones to pick up ambient noise and generate a cancellation sound wave to reduce or eliminate the noise. They typically have a battery-powered ANC circuit that processes the ambient noise and generates the cancellation sound wave.
Noise cancelling headphones can be effective at reducing or eliminating low-frequency background noise, such as the hum of an airplane engine or the rumble of traffic. However, they are not as effective at blocking out higher-frequency noise, such as human speech. Noise cancelling headphones can also affect the sound quality of the audio signal, as the ANC circuit can introduce some distortion or coloration to the sound.