Using a microphone, noise cancellation technology captures external sound and generates an anti-noise signal to cancel it out.
In earphones, there are two main types of noise cancellation:
Active noise cancellation (ANC): Active noise cancellation uses one or more microphones to pick up external noise and then generates an opposite sound wave that is played through the earphones. The opposite sound wave cancels out the external noise, making listening quieter and effective. This process is continuous and adjusts in real-time to cancel out the different frequencies of external noise.
Passive noise cancellation: on the other hand passive noise cancellation relies on the physical design of the earphones that blocks out external noise. A silicone or foam ear tip creates a seal in the ear canal, preventing external noise from entering. Over-ear headphones use a thick ear cup to muffle sound.
Most of the earphones and headphones now comes with both active and passive noise cancellation techniques to provide the effective noise cancellation. This can provide a more immersive and enjoyable listening experience by blocking out unwanted noise and allowing us to focus on the audio.