I examined the Operating noise of TAMIYA "SPRAY-WORK POWER AIR COMPRESSOR". I used the professional recording equipments (48kHz / 24bit). Regular air sound is due to the operation of the valve to release the pressure. Irregular air sound is due to the airbrush.
I do not feel annoyingly this sound. And I thought"AIR COMPRESSOR ANTI-VIBRATION MAT" is essential, because the bass noise is drastically reduced.