BB, I've been told that "noise in the head" is an entire field of science, ranging all the way from tinnitus (general ringing) to actual clear voices talking to you -- no kidding: some people actually hear voices, and a few unfortunately act upon them. There's a theory that there's some connection being made between side-frontal lobes that aren't supposed to connect that way (don't ask me: I'm just repeating a vaguely remembered conversation), but who knows.
I've read that sometimes the noise is loud enough that a doctor can hear it from outside, from the ear. But it isn't an ear malfunction -- it has something to do with the brain.
In minor ways, this happens to most of us -- you hear people talk about earworms? Something odd is going on there, and the more serious problems are versions of that. Drugs can cause a version of auditory hallucination -- that has happened to me, and it took years to get over it. No one believed me either if I tried to explain, so I just shut up about it, but it's a very real problem, like flashbacks.