Signed up just to add to this thread. What stood out to me here was some folks saying that closing off their ear made it stop, which is the case for me. The thumping started at night on Sept 18 while I was trying to sleep. It was sporadic and I thought it was my daughter stomping around on the floor above me. I went upstairs to check and everyone was asleep. It returned the next night, also sporadically. A few days later it came back, but was much more rhythmic and rapid, which is how it has been ever since. It comes ago and goes, apparently without any trigger that I'm aware of. In fact, it stopped just as I was starting to write this after being constant for the last few hours. I sometimes put in an earplug in the right ear, which tends to muffle it. Also being out and about makes it so I don't notice it, even if it is occurring. And as pointed out by some others here, if I close my ear off by pressing the flap with my finger, it goes away completely. Definitely not in time with my heartbeat. I have a slow resting HR and the thumping is quite rapid. I have suspected that it is related to sinuses, but I don't have any other symptoms for that. ... And now it has started up again as I write, but faint. So for me, it comes and goes, is rapid and muffled drumming-like, and can vary in loudness. I'm 60 but in excellent health; had COVID in July with mild symptoms and nothing since. While writing this, I thought I would try putting on Bose headphones that I have sitting here (not listening to anything) and the thumping stopped. So now I have another tool to deal with this, I suppose. I wish you all the best with your situation and that it is maybe annoying for you, but not worse. And that it goes away.