I have it, caused my hearing damage (non genetic). I've noticed some muscle relaxers will increase the sound, but when the meds wear off it goes back to normal.

Broadly speaking, I live in a quiet environment. Over there past few years it seems like it's gotten better. Like since I hear it slightly all the time my brain ignores it better. YMMV.

But yes, see a doctor about it. And don't freak out. What comes on suddenly may go away slowly too. My sudden episodes sometimes last two weeks, but they subside.