Is it normal to have multiple thinking sounds?

Esp when I'm tired (physically) or just been out, I need to lie down for a while/nap, and there'd be multiple thought voices going on like my original own voice thinking, sometimes two layered thought processes or even more (all my /thinking/ sound and nothing actually auditory) and a third background song that I know just shows up randomly. It's like public bg noise but not exactly. And 10 mins or so into lying down, they all suddenly disappear, I even forget what I was thinking of. Like I don't have to actually fall asleep sometimes I just have to "rest my head" and my energy is back. Is it normal?