What is the difference between a hearing aid and a cochlear implant?

First off there are some similarities between hearing aids and cochlear implants.  They both are powered by batteries.  They both require the user to wear a device on/ in/ behind/ near their ears. They both must be programmed by an audiologist. They both are used to treat hearing loss in both children and adults.

Although there are similarities between hearing aids and cochlear implants there are some very key differences.  Hearing aids are devices that amplify (increase the volume of) sounds and send them up to the brain through the whole auditory system; the ear canal, eardrum, middle ear bones, the tiny hair cells of the inner ear, and the auditory nerve.   Hearing aids can benefit people with all different degrees of hearing loss, from slight all the way to profound.  Hearing aids help to ease communication effort, reduce difficulty hearing and understanding, and lower the level of communication fatigue experienced by the user.  Hearing aids are used only during the day and at night the patient takes off the device completely.   There is no portion of the hearing aid that stays on / in the patient permanently.  There are no guarantees of how an individual person will do with a hearing aid.  Some patients report that with their hearing aids they have nearly “normal” hearing; others may only see modest improvements.  In general, however, a patient with better word understanding scores will see a greater level of improvement with hearing aids than will a patient with poor word understanding scores, even if their degree of hearing loss is worse.  How much improvement is “worth” wearing the hearing aids differs from patient to patient as well. 

Cochlear implants are devices with both an internal and an external device.  The external device picks up the sounds and bypassing the ear canal, eardrum, and middle ear, sends them to the internal device which connects to an electrode array that is implanted into the cochlea (inner ear).  Tiny impulses of electrical current are sent along the array from the internal device to stimulate the auditory nerve.  Unlike hearing aids, cochlear implants are available only to patients who have a very significant hearing loss in both ears. Current guidelines permit cochlear implantation in adults and children age 2 years and older with severe-to-profound hearing loss.  Infants/toddlers 12 to 23 months of age must have profound hearing loss in order to qualify for implantation.  Additionally patients must score in the “poor” range on word understanding and sentence understanding tests.  Also unlike a hearing aid, a cochlear implant is a very permanent part of the person’s life.  At night the patient would take off their external device but the internal portion of the cochlear implant will stay inside the patient’s head all day and night.  Although a person can choose to take off their hearing aids and go back to hearing as they did before the hearing aids, due to the way the cochlear implant surgery is performed and how the cochlear implant works, a person with a cochlear implant cannot choose to go back to hearing how they did prior to the cochlear implant.  Just as with hearing aids, there are no guarantees of how an individual person will do with a cochlear implant.  However, unlike with hearing aids, a person’s pre-implantation word understanding scores do not directly correlate with the expected level of success with a cochlear implant.  Choosing to be implanted is a decision that is not to be taken lightly, but it is also a choice that can have a truly amazing outcome for the right patient.