I installed a set of speakers for a supervisor the other day and the following day he comes up to me "hey i need to see you, my speakers don't work. they just make a click click click sound".
me:
you're probaly just doing something wrong. i tested them before i left
him: no, i don't think so.
I walk up to his PC and the "click" sound he was referring to was the normal mouse click sound you hear when clicking on something. :slap: I was like "i told you your sound works fine." He still insisted on testing them with some live audio. So I had to embarass him some more when I got that to work too.