Do you suddenly get up in the middle of the night hearing strange noises? Yes it can definitely be frightening, more so when you cannot find the source. Now consider for a moment that these sounds are coming from within you. Most people would be stunned to know that. Many of us do not even know that our internal organs can make sounds.
Let us try to see whether you actually heard these noises or not, and if you did, where did they come from. Now before anything, let us get this straight - yes, you actually heard those noises. No, they are not a result of a creative mind that imagined things in slumber. But having said that, it is also true that there is indeed no source of the sounds you heard. So what is it? Confused?
This is a classic case of tinnitus.