OP said:
I'm not saying I believe any of this, just saying, I can see where the theories stem from. I wonder if there are many metaphysical theories about other diseases or ailments, or just this one?
Study the history of medicine, and you'll see that in ancient times ALL diseases and illness were thought of as being caused by supernatural forces; the medicine man was literally the spiritualist in the community, the one who chased the evil spirits away with magic cures, spells, potions, liquids. This is not just primitive cultures (like as found in the Amazon in last century), but places like Egypt, Babylon, etc.
PS I have a form of tinnitus called gaze-induced pulsatile tinnitus, where I only hear the sound of blood pulsing in my ears when I look in extreme directions. Very odd, but avoidable.
Garden-variety tinnitus is actually tricky to determine the cause, as there's so many factors that can cause it. Stick with the mainstream medical sites, and see if anything seems likely (even stuff like smoking can cause it). Really nailing down the cause requires much testing, looking for underlying causes (high blood pressure, exposure to toxins, etc). The approach is to start with the least-costly rule-outs, and keep digging until you find the cause.