Greetings fellow Martian...
You are not alone. My hearing in my 'good' ear is quite sensitive to loud noises, etc. When I am in a noisy environment, try to turn up the TV to hear it, etc., my deaf ear has horrible tinnitus. It is to the point that I cannot stand to have the TV up to the point that I can hear it, totally avoid the radio in the car and have pretty much given up listening to my MP3 player. When I am around someone who talks loud, I have to stop myself from putting my hand over my good ear to block out the tinnitus in my deaf ear. Even a fan blowing in the room makes me crazy(er). I have had this from the moment I woke up after surgery.
I figured I was just somewhat of a rare case because my hearing was normal in my AN ear prior to surgery. Waking up deaf in my right ear (I had a translab due to location of the tumor), extremely sound sensitive (two people trying to talk to each other in the same room initially caused me severe pain), and having feedback in my deaf ear from the phone in my good ear certainly is a new experience. I have mentioned this to the neurotologist and audiologist.
When I went for my BAHA eval, (I am anticipating surgery mid September) they tested me to make sure I was really deaf in my deaf ear. I got a chuckle out of this, but they had to document it for insurance purposes. The sounds they put into my deaf ear were audible in my good ear. The audiologist explained why this happened. The only thing I remembered she said was that it had to do somethig with masking.
So fellow Martian, I too am affected by noises going into my good ear and find myself wearing an earplug to block out the noise in my hearing ear. Sort of ironic, isn't it? I plan to move forward with the BAHA figuring that if it makes the tinnitus worse (not sure how it could be much worse) I will just take off the processor and discuss it with the doctor. Someone gave me the name of a doctor locally that deals with tinnitus and biofeedback. I am already considering this an option.
I will see the doctor here in a few weeks and talk to them about this issue and also see if they think having a BAHA will make it worse. I'll let you know what they say.