Bugs in my head

Odd things going on in my head today. I woke up around 5am at which time the fridge just happened to be running its cooling cycle. It's one of those noises you don't notice until it stops. It went off shortly after I woke up, but was still lying in bed. Once it was quite there was effectively no noise in the house and no cars other environmental noise from the outside. Almost immediately I heard what sounded like very very faint radio static coming from my ceiling. Puzzled, I walked into a couple different rooms but couldn't get a line on where it was coming from. After I verified that there wasn't anything on in the house that would cause it I opened a window to see if it was something from outside. As soon as I did this the ambient noise from the rustling of the trees washed out the static. The trees aren't loud at all, and you wouldn't notice them unless you were specifically listening for them or something else very quite. At this point, I got a little nervous as my mind jumped to : what if I somehow got termites (despite the termite bond) and I'm hearing them eat my house? Slightly freaked, I put my ear to the wall in several places, but the sound didn't seem to be coming from there. After walking around a little more I stopped in the living room and tried a little experiment and tightly covered both my ears with my palms. Sure enough, I could still hear the sound. In fact, it was a little louder. So, the sound is, quite literally, all in my head. With most peoples ears, if you get into a virtually silent environment, you will hear a slight ringing. From what I gather this can be either tinnitus or your ear just making up something to send to your brain since it doesn't have anything else to send. I've never had this happen with a sound more like static though. I've had a head cold, so I wonder if this has anything to do with it. It's probably that, or the fillings in my teeth are picking up radio waves..... By the way, you should try putting your ear up against a wall that has an exterior face. It's wild what you can hear. In my case, it was the highway that's probably two miles away.