The difference between a cochlear implant and a hearing aid is a frequently asked question. Bionic ears and hearing aids are different. The difference between a cochlear implant and a hearing aid can be summarized as follows: Sound from hearing aids may not be perceived if hearing loss is severe. With a cochlear implant, sound waves are converted into electrical energy and transmitted to the auditory nerve inside the ear. This allows a person with hearing loss to perceive sounds. Hearing aids are not surgically implanted; cochlear implants are surgically placed inside the ear. Cochlear implants are used when a person does not benefit from hearing aids.