A<unk>  <unk>  is a surgically<unk> ed neuroprosthesis that provides a person who has bilateral moderate-to-profound sensorineural hearing loss with sound perception and an opportunity with therapy for improved speech understanding in both quiet and noisy environments. A<unk>  bypasses acoustic hearing by direct electrical stimulation of the auditory nerve. Through everyday listening and auditory training,<unk> s allow both children and adults to learn to interpret those signals as speech and sound. The<unk>  has two main components. The outside component is generally worn behind the ear, but could also be attached to clothing, for example, in young children. This component, the sound processor, contains microphones, electronics that include digital signal processor (DSP) chips, battery, and a coil that transmits a signal to the<unk>  across the skin. The inside component, the actual<unk> , has a coil to receive signals, electronics, and an array of electrodes which is placed into the cochlea, which stimulate the cochlear nerve. The surgical procedure is performed under general anesthesia. Surgical risks are minimal and most individuals will undergo outpatient surgery and go home the same day. However, some individuals will experience dizziness, and on rare occasions, tinnitus or facial nerve bruising. From the early days of<unk> s in the 1970s and the 1980s, speech perception via an<unk>  has steadily increased. More than 200,000 people in the United States had received a<unk>  through 2019. Many users of modern<unk> s gain reasonable to good hearing and speech perception skills post-implantation, especially when combined with lipreading. One of the challenges that remain with these<unk> s is that hearing and speech understanding skills after<unk> ation show a wide range of variation across individual<unk>  users. Factors such as age of<unk> ation, parental involvement and education level, duration and cause of hearing loss, how the<unk>  is situated in the cochlea, the overall health of the cochlear nerve, but also individual capabilities of re-learning are considered to contribute to this variation.
Cochlear implant
Middle ear implant
Bone-anchored hearing aid
Totally implantable cochlear implant
Craniofacial prosthesis
Direct acoustic cochlear implant
Brain implant
Facial implant