A generic cochlear implant includes external components, to be applied behind the ear, and internal components, to be inserted in the subcutaneous and close to the cochlea.
The installation of a cochlear implant requires the intervention of the surgeon. The most commonly adopted surgical operation for the insertion of a cochlear implant is mastoidectomy.
Available for both adults and children, today's cochlear implants represent a very effective audiological support, not only in the presence of medium-severe hearing loss, but also in the presence of deafness.
Inner Ear and Cochlea: a brief review
The inner ear basically comprises two hollow structures: the cochlea, which is the organ of hearing, and the vestibular system (or vestibular apparatus), which is the organ of balance.
Each of these organs is connected to the brain by means of a nerve: the cochlea via the cochlear nerve, while the vestibular system via the vestibular nerve.
A fluid, called endolymph, circulates inside the cochlea and the vestibular system. Rich in potassium, endolymph is essential for auditory perception and balance, as it plays a decisive role in the transmission of nerve signals / impulses from the " inner ear to the brain.
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Morphologically similar to a snail, the cochlea is in fact the center for converting sounds into nerve signals / impulses.
For the conversion process, it makes use of particular hair cells, dispersed in the endolymph; these hair cells are called the organ of Corti.
Once the conversion process has taken place, the organ of Corti and the endolymph interact with the cochlear nerve, which at this point transmits the newly formed nerve signals / impulses to the brain for their final processing.
The difference lies in the perceived sounds: the cochlear implant excludes some sounds, which the human ear perceives instead.
Despite this, cochlear implants recognize the most "important" sounds for the daily life of a human being, from sound signals of danger or that conceal a danger to linguistic sounds, etc.
Cochlear Implant: is it a Hearing Aid?
A cochlear implant is not a hearing aid.
In fact, unlike hearing aids (or hearing aids) that amplify sound, cochlear implants convert sound waves into electrical signals / impulses, effectively simulating what the cochlea does when it converts sounds into nerve signals / impulses.
According to neurophysiologists, nerve signals / impulses are comparable to electrical signals / impulses.
For further information: Hearing Aids: What are they?Cochlear Implant: How It Works in Brief
Briefly, a generic cochlear implant picks up the sounds present in the external environment, converts the sounds picked up into electrical impulses / signals and, finally, transmits the newly generated electrical impulses / signals to the cochlear nerve, stimulating it.
Stimulation of the cochlear nerve is what guarantees the perception and recognition of sounds.
Synonyms for Cochlear Implant
The cochlear implant is also known as an artificial cochlea or bionic ear.
History of the cochlear implant
The principle of operation of cochlear implants is based on a discovery, which took place in 1957, according to which the electrical stimulation of the auditory system guarantees the perception of sounds.
From after 1957, numerous researchers began experiments for the development of electronic devices that, in some way, stimulated the cochlea and the connected nerve.
These experiments led, around the end of the 1970s, to the creation of efficient and useful cochlear implants for those who complained of severe hearing problems.
Despite this, the recognition of cochlear implants as therapeutic aids to hearing impairments and their approval by the medical community only date back to the mid-1980s.
Initially, the FDA (i.e. the Food and Drug Amnistration) only approved the use of cochlear implants in adults. Then, also thanks to the creation of increasingly advanced devices from a technological point of view, it approved their use even in children at least one year old (it was 2000).
From 2000 to the present day, the installation of cochlear implants is an increasingly widespread therapeutic solution.
on which the transmitter resides. Its function is to convert the sound signals from the external transmitter into electrical signals / pulses.
Through the incision of the mastoid process, the surgeon creates an access to the internal structures of the ear, access that allows him to apply the receiver / stimulator in the subcutaneous and the electrode system on the cochlea.
Cochlear Implant: Duration of Installation
Generally, the procedure for installing a cochlear implant takes 60-75 minutes. However, in some situations, it can take more than two hours.
Hospitalization, Discharge and Checks
At the end of the surgery for the installation of the cochlear implant, a maximum hospital stay of 3 days is foreseen.
During this time, the medical staff is responsible for periodically monitoring the patient's health conditions.
During the first 24 hours of hospitalization, the operated subject is likely to feel confused or lightheaded and experience headaches or dizziness; all of these disorders are normal consequences of general anesthesia.
After the discharge and for about a month since the intervention, the patient has scheduled a series of post-operative checks.
Unilateral and Bilateral Cochlear Implant
Depending on whether the deafness / hearing loss is unilateral or bilateral, the installation of a cochlear implant can affect one or both ears.
If the installation involves only one ear, it is referred to as a unilateral cochlear implant; if, on the other hand, the installation involves both ears, it is referred to as a bilateral cochlear implant.
Clearly, in the first case, patients will wear only one electronic device applied to the ear; while, in the second case, they will wear two, one for each ear.
Cochlear implant in the child: at what age can it be done?
The minimum age for the installation of a cochlear implant in the child is 12 months.
The ability to install the aforementioned device so early stems from the enormous advances in medical technology in the field of electronic hearing aids.
* N.B: the vestibulocochlear nerve is the eighth cranial nerve. The cochlear nerve and the vestibular nerve originate from it.
