It can’t be heard from 1cm away I doubt that. A while back I removed all of the moving parts from an old 486 and netbooted it, only to find out I could actual

It can’t be heard from 1cm away I doubt that. A while back I removed all of the moving parts from an old 486 and netbooted it, only to find out I could actually hear the network card making very faint screeching noises whenever there was network activity. You've probably heard the same effect on a much larger scale, at much lower frequency, when you hear the 60Hz hum of a "silent" transformer.