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, so as to achieve the effect of noise reduction. Active noise-cancelling headphones have a noise-cancelling circuit that counteracts external noise. Most of them use a larger head-mounted design, which can block external noise by using earplugs and earphone shells to block external noise for the first round of sound insulation. There is ample space to install the active noise cancellation circuit and power supply.

Passive noise-cancelling headphones mainly block external noise by surrounding the ears to form a closed space, or using sound insulation materials such as silicone earplugs. Since the noise is not processed by the noise reduction circuit chip, generally only high frequency noise can be blocked, and the noise reduction effect on low frequency noise is not obvious.