A bone-anchored hearing aid (BAHA), also called a bone-anchored hearing system or bone-anchored auditory implant, is a type of surgically implanted hearing aid. Instead of amplifying sound outside the ear, a bone-anchored hearing aid will conduct sound via vibrations to the inner ear. Not all patients are good candidates for bone-anchored hearing aids since they are considered specialty hearing devices for particular types of hearing impairment. Typically, a bone-anchored hearing device is the best fit for individuals who have at least one normally-functioning inner ear. Good candidates for this type of hearing loss treatment are patients with single-sided deafness or significant middle or outer ear malformations that impact hearing. During the implantation of a BAHA, a surgeon will place a tiny titanium implant into the mastoid bone, which sits behind the ear. The implant is roughly 3-4 mm in size and is attached to an external sound processing device.