Surlypacer - consider acupuncture from a therapist trained in traditional chinese medicine. I was surprised to learn from mine that the particular quality of the ringing (hissing, more bell-like, etc) can let them know which meridian is out of balance, and they can use the needles to adjust that. You've already ruled out ear problems, time to try something new!

btw, both Wahine and Pike are trained in the manner and may be able to give you more tips about what to look for in a therapist, and how successful you might expect treatment to be.

Sending butterflies to help, and hugs,
~T~