What Are Noise Canceling Headphones?

Noise-cancelling headphones refer to a kind of headphones that use some method to reduce noise. There are two types of noise canceling headphones: active noise canceling headphones and passive noise canceling headphones.
The active noise reduction function is to generate anti-phase sound waves equal to the external noise through the noise reduction system to neutralize the noise, thereby achieving the effect of noise reduction. Passive noise-cancelling headphones mainly block external noise by surrounding the ears to form a closed space, or using sound-insulating materials such as silicone earplugs.