This has happened to me like 5 times in my life...
I'm sleeping. All of a sudden its like I'm awake, in my head I'm thinking im not sleeping, I know I'm in my bed awake but I can't open my eyes or mouth. Then my hearing goes weird, all I hear is...well closest way to describe it is that its almost identical to the sound of the inside of those big seashells, that oceany sound but in my ears its very distant. Then I feel like something is hovering over my body and breathing on me (just got chicken skin simply typing this). The whole time I'm telling myself in my head to wake up and look around, but I can't. I try to call out but its like my mouth won't open no matter how hard I try to, same with my eyes. It's so creepy. It's like I'm asleep and awake at the same time. Eventually I do "snap out of it". Two times my fiance "woke" me up from it....once because she said I sounded like I was groaning in pain and the other because I apparently was mumbling "wake me up" repeatedly in a voice she said sounded like I was going to start crying...weird shit was that I remember doing that. Clear as day too, but I couldn't wake up on my own. I know this sounds crazy lol. It hasn't happened in like a year or so.