Stress usually causes it and low magnesium. Google thumping and ringing in the ear and magnesium. I've had it and noticed it was stress induced. So I started doing de stressing techniques like exercising, meditation, hiking and walking, enjoying nature and reading books (anything that helps you relax), but I also started taking magnesium vitamins and it started going away. Just research low magnesium and thumping in the ear and there is a lot of info out there on it.