Helping People Communicate: Cochlear Implants By Charles Paone, Speech/Language Pathologist May is "Better Speech and Hearing Month" and "Helping People Communicate" is the new theme for making people aware of communication and its importance in daily life. Nature’s Hearing System Eardrum: incoming sound waves vibrate this membrane at the end of the ear canal. Malleus, Incus, Stapes: the eardrum movement pushes and pulls these bones that are connected to the cochlea. Cochlea: fluid inside this organ moves responding to the vibration created by the middle ear. Hair Cells: specialized structures in the cochlea sense movement in the fluid. Their physical location helps the cochlea relay information related to pitch and tone. Damage to these hair cells is the most common cause of hearing loss. Auditory Nerve: sound signals are transmitted to the brain by the auditory nerve. Hearing is taken for granted by so many people. If you are born deaf, or lose your hearing, you have a major challenge in this auditory world. Cochlear implants, a translator of sorts, helps deaf people hear and converse. The implant, parts of which are embedded under the skin, increases the fluctuations of voices and transmits the voice/speech into electrical signals. The signals bypass the inner ear and stimulate the auditory nerve, that is still functioning, and send the signals to the brain. Cochlear Implant Hearing System This system bypasses much of the inner ear and stimulates the auditory nerve directly. Microphone: detects incoming sounds. Speech Processor: converts sound into electrical code. It is programmed and calibrated through a process called mapping. Coil/Receiver/Stimulator: incoming signals from the speech processor are transmitted via radio waves through the skin. Electrodes: electrodes embedded in the cochlea stimulate the auditory nerve fiber. Auditory Nerve: sound signals are transmitted to the brain by the auditory nerve. Once the signals from the cochlear implant are in the brain, the impulses are reassembled (scientists don’t know how) into a speech pattern. Cochlear implants began appearing in the 1980’s and were relatively primitive. They could detect a few sounds and assisted people with lip reading. Today, however, they allow more than 70,000 people to communicate and even hold telephone conversations. As the technology advances, so does the rehabilitation potential. Cochlear implants function differently than hearing aids. Hearing aids amplify sound. Cochlear implants are recommended only for profoundly deaf individuals, and serve as a hearing assistant, reinterpreting sounds for the brain that would be normally transmitted by the bones, membranes and hair cells of the inner ear. Cochlear implants are expensive. The cost of evaluation, surgery, the device and rehabilitation is usually in excess of $70,000. Many insurance companies now cover this cost provided that the individual meets specific criteria. To obtain maximum benefit, a person must receive the device soon after a total hearing loss, before the brain and auditory nerves "forget" what sound is and what the brain should do with sound. Cochlear implants continue to be problematic. They can’t decipher music. They provide only an approximation of human speech. They are effective only in a quiet environment, and there is no dependable predictor of how well a person will perform with the device. Cochlear implants have been placed in over 20,000 deaf children. In 2002, the U.S. Food and Drug Administration approved the use of implants in children as young as one year old. Children with implants show great progress in learning oral skills of speech and language production. When a child has an implant, they can communicate in many different ways, and the world is open to them far greater than if they were to use only sign language or cued speech. Cochlear implants have provided another option for the deaf community. Web sites: agbell.org hei.Org nad.org