So, although this doesn't occur often, this sound issue seems to have come back once more. I'll start from the beginning. One day my dad suggested a sound machine that produced white noise while I go to sleep. It worked very well and I was pleased with the outcome.
This is where my issue starts. Sometimes my brain, I think, perceives sounds out of it from out of the blue. They sound very real, as if outside of my room/house, or somewhere near me, and at first I really thought the sound was real. It took me a while to doubt it and it finally went away. I wish I could describe what these sounds are like. They can go anywhere from beeps, screeches and hums. They can be real simple or very complex as if you're listening to background music of a song. They're generally short, however, and repeat extensively and the volume can go really low to really loud anytime, especially after you realize it's fake. No, I have never heard a voice come out of this machine.
This morning I woke up to something like this. I haven't used the white noise last night nor have I used it in a couple of months. Well, I heard a very complicated, almost annoying sound in my head and it just repeated over and over! I didn't process that it wasn't real yet, so I fell back asleep pretty quickly. I woke up half an hour before my alarm and the exact same rhythm was still there in my head. Maybe a minute later I finally realized it wasn't out of my house or out of my room and I tried to figure out ways to forget about this noise. I tried staring at something intensely or watching my pet leopard gecko. The strangest thing is that it felt like I was battling turning the volume off in my head. For example, let's say you're playing a YouTube video. As the video is playing, you double click the volume button so that it mutes the video real quick and the volume goes back just as quickly, but continues right into the beat it wants to play. That's the best way I can describe it.