What Causes Rattling Sound In The Head?

There is a rattling sound in my head. I can only hear it when I jump around. It kind of sounds like two marble clinking around. It's usually at the back or left side of my head. What's wrong? I am 13. I am usually very active. And I right now am recovering from what I think to be a pinched nerve. Ive never had this problem before. I am 5'5. I weigh 130 lbs( I'm tall) I've also had a little bit of a headache but that's probably just from the crying(I'm really scared that this is serious). Please help. And if you don't know what this is have you ever heard of anything like it before?