Who else hears it?

So, I've had my hearing checked and there is some loss which I can only attribute to listening to really, really loud music during my teenage and young adult years. Sitting in front of monitors and amplifiers does, indeed, have its consequences.

However, I spoke to the audiologist and it seems that there's a very small portion of the population that can hear this frequency of "hum," and my moderate hearing loss doesn't really explain what I'm hearing. For me, it's often a rumbling sound as if deep, deep inside the earth. Sometimes, it sounds almost like distant thunder in the atmosphere.

I completely understand that senses often go haywire when there is some sort of damage or loss. When I was working in an actual photography dark room, my professor explained that we would "see" things like patterns, tracers, and colors while in the total darkness of the developing room. The explanation was that the open eyes were conditioned to "see" things and that the brain had to satisfy that expectation by making up things for us to "see" in the total darkness. But, I don't believe that this is what is generating the "hum" for me. I believe that it's an actual sound frequency, and the audiologist seemed to validate that as far as they were willing to.

Anyone else experiencing this?