I get this all the time. It is annoying. It's bad enough to have to put up with tinnitus, but then also to hear your own heart beating is realllllly annoying. Mine is caused by a build up of fluid in my ears. My doc had a simple remedy, I just apply some peroxide on a Q-tip, just at the opening of my ear and it draws out the excess fluid. I have to do it about every other night after my shower. My mother also had this problem, but her's was caused by excess build up of wax. Ick!