Sometimes, when playing CoD4 while wearing headphones, i'll pick up what sounds like interference. It seriously sounds like people talking sometimes, but I don't know where it's coming from. Would it be possible that anything could actually be causing this, or am I just going nuts?

Attenuation of signals. I used to get some kind of asian radio signals through my speakers. No big deal really, just adjust where your speakers/phones sit to break the signal path.

Well this brings up an interesting point, Can one pick up a radio signal i.e. CB on a computer?