For patients with severe to profound sensorineural hearing losses, hearing aids are often not able to improve speech understanding. While very powerful hearing aids exist, that increase intensity to very high levels, they may not improve hearing if there are too few or no remaining sensory cells to stimulate. Therefore, the sound information cannot be properly delivered from the ear to the brain. For these patients, a cochlear implant, or ''bionic ear'' may be recommended. Cochlear implants attempt to restore hearing to people with severe to profound hearing loss by delivering electrical stimulation directly to the nerve, bypassing the damaged structures of the inner ear. Cochlear implants are prosthetic devices with internal components that are surgically placed and external components that require fitting and programming. Cochlear implants are considered the only medical treatment for severe to profound hearing loss.