Automatic telephone switch:
-
Noise in, Grind wood with a grinder
-
Air compressor, air blow
-
Printing press
-
Circular knitting machine
-
Box making machine
-
Automatic telephone switch
-
Crusher
-
Electric generator (hum)
-
Working,, Welding transformer, turning on
-
Letter press
-
Drone in a mine tunnel, Factory atmosphere
-
Work, start, jamming, Generator
★★★★★