Thanks to the huge steps humans have taken in science, technology, and the medical industry, we have something called Cochlear Implants. These implants assist in providing a type of sense of sound to someone who is legitimately deaf, of profoundly impaired at a hearing.
The units consist of an internal portion, which is surgically inserted under the skin, and the second part that sits behind the person’s ear.
The cochlea is the auditory part of the inner ear. It is a spiral-shaped cavity within the bony labyrinth. The main component of the cochlea is the organ of Corti, which is the sensory organ of hearing. It is distributed throughout the partition that separates fluid chambers inside the coiled and tapered tube of the cochlea.
How the Implants Work
Bypassing most the peripheral auditory system, that receives sounds, which then converts that noise into movement of hair cells within the cochlea. Potassium ions get released by these hair cells, and the potassium then stimulates other various cells within us to release the neurotransmitter, glutamate, which triggers the cochlear nerve to send a signal to the brain, thus creating the experience of sounds.
The implant, however, picks ups these sounds that are unable to be heard without hearing aid, digitizes them, then the digitized sound is turned into electrical signals, these signals get transmitted through electrodes that are embedded within the cochlea.
The electrodes then electrically stimulate the cochlear nerve, thus causing it to send these signals to the brain, resulting in the ability to be able to hear.
Parts of the Implant
There are multiple variations of the implant, but overall, they will contain these certain components. They are equipped with one, or possibly more, microphones which pick up sound within our environment.
They also have a speech processor, and this helps filters noises and sounds and prioritizes them with clear speech being the primary concern. A transmitter is also equipped, which sends power, and the sound signals that are processed, across the skin into the internal device. Electromagnetic induction completes this process.
Implants also have a stimulator and a receiver that receives and send signals of speech to one another. The last main part is an electrode array, which is embedded within the cochlea.
The surgical procedure that is the primary way of inserting cochlear implants, is called mastoidectomy and accompanied by the facial recess approach, or MFRA. There are other methods used too, like going through the supramental triangle approach. It is not currently known which method creates better results, or which one is safer.
Patients are usually put under general anesthesia for this procedure. Complications that are a result of this operation are about 12%. Some possible risks would be infections, device failure, and complete or partial, facial paralysis.
The FDA only authorizes these implants for people who are deaf completely in both ears. It is not currently authorized to perform this procedure for people suffering from deafness in only one ear.