Even the smallest of sounds that a machine makes has a *story behind it... if you're listening. A hard ratcheting sound made by a printer often means a bearing on a drive roller has worn and the teeth are *slipping across each other instead of meshing as they should. The sound made by an internal combustion engine whose air/petrol mixture is too rich or too lean (with petrol) will make distinct sounds which mechanics trained to adjust carburetors rely upon and adjust for/against accordingly. Although the *dirty white noise coming from the servers in my office aren't necesarilly telling me they are running, it is an eerie, lonely silence on the days when I have the opportunity to shut them all off. I know the sound of a computer hard drive's actuator arm that is out of alignment/failing and also a cooling fan being overcome by dust or internal wires have fallen against the spinning blades.... they are all cries for help!

Jackie, your only concern is that you're starting to talk back... but singing along with your printer (especially a dot matrix printer spitting out a spread sheet) is OK.