Why can't I hear myself snore?

This question came in from caller Stan. Luckily, Chris Smith was able to dream up an answer. 

Chris - Brilliant question. The answer is Stan that when you go to sleep your brain diengates a lot of the flow of sensory information coming back into it. A good example of this is why you don’t act out your dreams for example. We know that we all dream; we do it every night and we dream many many times a night. Probably about 20 times a night you have a dream, but you don’t find yourself stalking people round your house, jumping out the window, that kind of thing because there is a specific structure in your brain stem, which is called the sub-coerulea region. And when you go to sleep and start to dream, this activates, and it disengages the flow of information coming back out of your brain to tell you muscles what to do, and it also damps down the flow of information coming up your spinal cord coming into you. So you’re effectively disengaging your sensitivity to the things that you do yourself.

There’s also another region of the brain which is where what’s called the parietal lobe, and the occipital lobe, and the temporal lobe all meet this area of the brain. This has a strong ability to suppress any sensory information coming into your body. You can’t tickle yourself, for example, because this area knows that you’re about to tickle yourself and it says to your brain, to your consciousness, in a minute I’m going to tickle myself. When you feel the tickle sensation coming in it won’t surprise you; you’re expecting it, and because you’re expecting it it doesn’t arouse you. It’s the same with your snoring. You’re making those noises yourself; you’re suppressing your own sensory system so you are not aroused, or woken up, or stimulated by that sensation. But when someone else does it, because it’s unpredictable and unexpected, we notice it.