One of my ears makes a crackle inside when i hear a louder noise. also rings on and off for years. jaw tight as well. what could cause this?

Tinnitus: Hello. While ringing or tinnitus is a relatively common complaint, it still needs to be evaluated. If it is occurring in just one ear, a more detailed examination is needed. See your ENT doctor. A complete audiometric evaluation will be helpful to determine a cause. Also jaw symptoms make you think of bruxism or teeth grinding. That has been associated with tinnitus and tmj. Good luck.