What Causes Progressive Hearing Loss?

I am a 32 year old woman and have had progressive hearing loss in my left ear. Within the past few months it seems to be getting worse. It actually surprises me to have problems with my left ear because as a child I always had problems with my right ear, such as continuous ear infections and rupturing the eardrum due to a slight electric shock from a light switch. I experience tinnitus very often, the kind of popping (going through a tunnel) feeling then a very loud ringing or buzzing sorta sound. I'm waiting for the approval of my insurance company to go to an audiologist, but my primary Dr. says there are 2 shadows in my ear and there is some slight bubbling on the top of the eardrum and there is some sort of shadow (not really sure what she meant by that, I may have misunderstood that last part). Any help or photos would be greatly appreciated!