Eric, I suggest you email Dr. Chang (Stanford University Medical Center neurosurgeon and leading CyberKnife [CK] practitioner) at sdchang@stanford.edu. He will review your MRI and other test data and consult you by phone for free.
Adding to the useful info Paul noted, CK usually preserves serviceable hearing when treating small tumors. The AN's close proximity to your cochlea may reduce your odds of serviceable hearing preservation, but Dr. Chang can quantify your risk, and a second opinion is a good idea. Generally speaking, CK provides a little better odds of hearing preservation than GammaKnife. Considering you are already deaf in one ear, I would advise you get CK to increase your odds of preserving your hearing in your right ear. Choose a doctor who has tons of experience with CK. If you can travel, Stanford University Medical Center and Dr. Chang are the gold standards for CK treatments.
Best wishes,
TW