you don't say if you are pre or post treatment, but muffled telephone voices were what lead me to the discovery of my AN. In fact, it was my only symptom.
Although I had diminished hearing in my left (AN) ear, I actually had fairly good hearing and very good word recognition; only phone voices were an issue for me. Wish I knew the explanation for that, but I don't. Now, post op, I have lost the entire hearing in my left (AN) ear. I had retrosigmoid surgery, in the hopes of saving the hearing level I had prior to surgery, but in my case, the AN had grown and wrapped itself around the hearing nerve. My surgeons felt it was better to remove the entire AN and "kill" my hearing nerve entirely, than to save my diminished hearing and leave part of the AN.