Hi Neal,
I think it is a good idea to wait until after surgery, with a bit of luck you won't need a BAHA. Anyway sorry if I wasn't clear, The hearing you get from a BAHA is only as good as the non AN side [ that still sounds confusing ]. When I had the infection I could not hear well out of the good ear, so the BAHA didn't work that well. The answer to the second question is, If you touch the BAHA accidentaly or deliberately while it is switched on it starts to whistle. MY husband always teases me when this happens and says " I think you are picking up Rangoon". Also if it is windy it starts to do the same thing. I still get tinnitus but I am used to it now, the BAHA doesn't change that. The unit also comes in 4 different colors, so it blends in well with your hair. Jeez I should be getting a "kick back" from the BAHA guys. Anyway I hope this helps and let me know if you want more info.
Cheers
Lainie.