Has anyone experienced this? When I'm working on my computer, suddenly, I hear a really loud whistle. I can only describe this as the same sound as a guy would give out, in appreciation of a good looking woman: a really loud "Wolf Whistle". I don't know if this is a virus or malware or what the heck it is; and, the sound just comes and goes, sometimes I don't hear it for a few days, then, zap, it comes back again. Can anyone tell me what this is and how to get rid of it?