What Implant Is Used To Restore Hearing In Right Ear?

A friend of mine had major surgery to remove a mass in the side of his face, which required removing the right salivary gland along with the right eardrum, in order to make sure they got it all. Now my friend is going to get some kind of an implant to restore his hearing in his right ear. What types of implants would be the choices among most ENT surgeons for this type of surgery to restore hearing for a person who no longer has an eardrum?