The investigators are studying a new way of doing cochlear implant surgery called "Percutaneous Cochlear Implantation". In this surgery, instead of doing a mastoidectomy where about 30ml of bone is removed, the investigators use image-guided technology (similar to GPS systems used to guide automobile travel) to drill directly from the surface of the skull to the cochlea, removing less than 2ml of bone. To use this technique, three markers (or anchor screws) are screwed into the bone around the ear. Next, an x-ray of the head (called a CT scan) is taken. Using this CT scan, a path to the inner ear (cochlea) is planned and a drill guide (Microtable) is made that mounts on the anchor screws. A drill will be attached to the guide and used to drill a path from the surface of the skull to the inner ear (cochlea). The implant electrode will be threaded through this path. All of these procedures take place under general anesthesia.