I used to wonder if I was hearing people on a radio talk show when trying to sleep. I also wondered if my one amalgam filling was somehow picking up radio waves and causing me to hear it, but I decided it was my tinnitus (ringing ears) combined with a hint of imagination and paranoia. I wonder now if this was an auditory illusion, since I get visual ones while trying to sleep.

On a side note my tinnitus seems to have been cured by going gluten and dairy free, so everything is silent once more.