Finally went to the audiologist yesterday, who was very helpful.
Good news is that the ears seem to be okay except for a bit of loss in the upper frequencies which may not necessarily be due to the work I've been doing. We talked about the psychological implications of tinnitus and how to deal with it. (It has got a bit better, since I've reduced the hours).
She thinks that maybe I've been working too hard, that certainly the hours I had been doing the studio work were too much and that I need to take more breaks and relax more. Who'd have thought?! Reminds me of the Velvet Underground line: "Some people work very hard, and still they never get it right." And also begs the question: have I been motoring instead of sailing? (At the Water's Edge).
The other good news is that I reckon I could be finished by today or certainly tomorrow. Not before time. (Yeah, I know, you've heard it all before).