I had this same problem, and FOUND THE ANSWER! I tried everything, and an ENT doctor even told me I'd have to live with it the rest of my life, but it turns out, all I needed was a Chiropractic adjustment. I went to Dr. Toy in Lawton, OK, and he worked wonders. My hearing came back A LOT after the first adjustment, and the sound wasn't as loud, but after a couple more adjustments, the sound completely went away a few months later. I think an artery was out of line or twisted or something like that. Dr. Toy graduated from some school called Logan out of Missouri, so I'd try to find a Logan grad in your area. He was old school in that he popped my neck (didn't hurt) 2 different ways. Some chiropractors use little tools or whatever. Get an old school one who just pops you back in place.
Is it Pulsatile Tinnitus? I've always wondered what that is. I've heard about it but never took the time to look it up. I was about to answer with Autophony, but I guess that may be too broad of an answer.
Its called pulsatile tinnitus. Tinnitus can be challenging to get rid of as there are many reasons for it. TMJ (Jaw), ear infection, head injury, allergy, drug reaction, etc.