There are many ways to reduce the noise of pneumatic grinder, such as sampling, filtering, noise gate and so on.
Sampling noise reduction method of pneumatic grinding machine
The sample feature of noise is extracted (sampled), and then the noise signal is removed from the original audio signal, which has little damage to the original sound.
Filtering and noise reduction method of pneumatic grinding machine:
A filter is used to block the frequency band of noise in audio, but the available audio in the same frequency band with the noise will also be blocked and destroyed. It has a certain destructive effect on the original sound.