Methods of Headphone Noise Reduction
There are two ways to reduce noise in headphones, active noise reduction and passive noise reduction.
The active noise reduction function is to generate a reverse sound wave equal to the external noise through the noise reduction system to neutralize the noise, thereby achieving the effect of noise reduction. Active noise-canceling headphones have a noise-canceling circuit that counteracts external noise. Most of them use a larger head-mounted design. They can use earplug cotton and earphone shells to block external noise and perform the first round of sound insulation. There is ample space to install active noise reduction circuits and power supplies.
Passive noise-cancelling headphones mainly form a closed space by surrounding the ears, or use sound-insulating materials such as silicone earplugs to block external noise. Since the noise has not been processed by the noise reduction circuit chip, it can generally only block high frequency noise, and the noise reduction effect on low frequency noise is not obvious.
The three noise reduction measures usually used to reduce noise, namely noise reduction at the sound source, noise reduction during propagation, and noise reduction at the human ear, are all passive. In order to actively eliminate noise, people invented the “active noise reduction” technology.