Machinery can be loud and a milling machine is no exception. Even worse is a CNC milling machine where an operator may need to stand nearby for hours. If the constant sound can be tiring and ultimately damaging. In this video, the sound level of the Precision Matthews PM25MV milling machine (similar to the Grizzly G0704) is collected in dBA, as the spindle speed is adjusted, at the distance of a CNC operator. These measurements may also serve as a baseline for subsequent measurement to estimate bearing condition.