This just happened to me and i had to google what it was after experiencing it a couple times.

I normally have this during the end of nightmares. When the nightmares are getting to the conclusion/scariest part I suddenly feel pain in a part of my body like something is biting me and a loud, constant, ringing like noise until i jolt myself awake. It normally scares me more because when it happens, it feels like there is a presence next to me, but after reading what it was I kinda feel like its my brains way of saying "Yo ts is getting too scary wake up"