In the Russian Federation, according to statistics, approximately 12 million people with various hearing impairments live. Hearing impaired and people with complete hearing loss experience a number of difficulties in ordinary everyday life. This limits their opportunities and participation in public life. A particularly negative effect on the personality is manifested in those people who were born with normal hearing, and later, due to some circumstances, completely deafened, or their hearing decreased sharply.
For hearing-impaired people, hearing aids have been developed. Most patients use them, but sometimes their use gives too little effect. In the case of sensorineural hearing loss, a cochlear implant can help patients. To understand how it works, first we’ll understand how the ear works and why we hear, and also briefly dwell on the types of hearing impairment.
Why do we hear?
Sound is conducted through the outer and middle ear. The sound wave leads to vibration of the eardrum. Further, she transfers this vibration to a chain consisting of auditory ossicles - this is a hammer, anvil and stapes.
From the stapes, which is located at the end of the ossicles of the middle ear, the vibrations pass into the cavity of the inner ear. It has the shape of a snail and is filled with liquid. Sensitive hair cells are located in this cavity, which transform mechanical vibrations into nerve impulses. These impulses enter the brain through the auditory nerve, where the formation and perception of the sound image that we hear takes place.
Why does hearing impairment occur?
Hearing problems occur if violations occur at some stage in the formation of the sound. So, if the sensitive hair cells of the inner ear are irreversibly damaged as a result of some kind of trauma or illness, then complete deafness develops. It can be postlingual if, by the time deafness develops, the child has already learned to speak, or prelingual if he has not yet mastered the speech.
Types of hearing impairment
Features of hearing impairment have their own classification, which is determined depending on the degree, location and the moment of deafness.
According to the degree of hearing impairment, they are divided into total deafness and hearing loss, if the perception of sound occurs, but it is difficult. Hearing loss happens:
Sensorineural neurosensory occurs due to hearing problems resulting from a disturbance in the inner ear or conduction of the auditory nerves. The degree of such disorders ranges from mild to complete deafness.
Conductive hearing impairment occurs due to problems that have arisen in the outer or middle ear, due to which the conductivity of sound vibrations is impaired and they are distorted or not conducted at all into the inner ear. This can be damage to the eardrum, sulfur plug, etc.
By age of onset, these problems can be:
By localization, deafness can spread to one ear or both, then this hearing loss is called binaural.
Indications for cochlear implantation
Cochlear implantation is indicated in the following cases:
- With deep sensorineural bilateral deafness.
- With a low threshold of perception in the case of using sound devices with binaural hearing aid.
- In the absence of speech perception in the case of optimally selected hearing aids for three months, with bilateral deep sensorineural hearing loss.
- In the absence of cognitive problems (impaired mental activity of a different nature).
- In the absence of mental problems.
- In the absence of various somatic diseases.
Contraindications and limitations
This type of implantation is ineffective in case of hearing loss, which occurred as a result of neuritis of the auditory nerve or hemorrhage in the temporal or stem lobes of the brain. Cochlear implantation in these cases will not bring the desired results.
It does not make sense to carry out the operation in cases of calcification of the cochlea (deposition of calcium salts) or its ossification (bone germination).
Cochlear implantation does not make sense if patients with hearing loss have lived in absolute silence for a long time (years). In this case, the operation will not bring the desired effect due to the fact that with a prolonged absence of stimulation, the branches of the auditory nerve atrophy and cannot be restored.
In addition, contraindications are:
- Inflammatory processes of the middle ear.
- The presence of perforation of the eardrum.
- The safety and working condition of hair cells, which is determined by the method of otoacoustic emission.
- With prelingual deafness - the age of the child is more than 6 years.
- In post-lingual deafness, a period of deafness lasting more than a period of normal hearing.
What is a cochlear implant?
The system consists of two parts, which are not interconnected by any physical methods. One part is attached behind the outer ear and consists of a microphone and a processor (in modern models they are combined), as well as a transmitter, which is attached to the skin like a magnet. The second part is internal, and is a receiver. It is fixed in the temporal bone. Actually, this operation is the installation of the receiver - cochlear implantation.
How does the system work?
A microphone attached to the outer ear picks up sounds and transfers them to the speech processor located in the same place. In the processor, the received sounds are encoded and converted into electrical pulses. Then they, through a transmitter attached to the skin, enter a receiver located in the temporal bone. From there, they enter the cochlea through the electrode and act on the spiral ganglion of the auditory nerve. Thus, the patient is able to perceive sounds.
The total cost of a cochlear implant, examination, surgery and postoperative correction is determined specifically for each patient. The number of examinations required depends on the medical history and general condition of the patient. So, for example, for patients with a history of meningitis, magnetic resonance imaging is mandatory, which will determine the condition of the temporal bones. For other patients, such an examination can be omitted. Also, sometimes (not everyone) requires a consultation with a geneticist or a neurologist. This all affects how much cochlear implantation costs. Its cost is approximately 1 million 300 rubles. But for citizens of the Russian Federation, such an operation can be performed free of charge under the quota.
The cost of hospitalization and hospitalization is paid separately and depends on the rates of the selected institution.
Necessary examinations and surgery
- Inspection of an ENT doctor.
- Consultation of an otoneurologist.
- Consultation of a sound educator.
- Promontorial test.
- Otoacoustic emission.
- Evoked auditory potentials.
- Computed tomography of the temporal bones.
- Standard laboratory examinations, as for any surgical intervention (general analysis of blood and urine, blood glucose, biochemical blood test).
The operation itself takes approximately 1.5 hours. The implant is fixed in the temporal bone of the ear region, and the electrodes are inserted into the cochlea. Then, for 7-10 days, dressings are performed and sutures are removed.
You can turn on the system after 3-5 weeks. The first setup can be done no earlier than a month after the operation. It is very important to carry it out carefully and not cause negative emotions in the patient when he returns to the world of sounds.
Possible simultaneous cochlear implantation immediately in both ears. At the same time, a separate independent cochlear system is placed on each side. Examination and rehabilitation period are the same as with unilateral implantation.
After the operation "cochlear implantation" rehabilitation is an integral stage. After the speech processor is connected, it must be properly configured and taught to the patient to perceive sounds and recognize these sensations so that he can use the information received to develop speech. Rehabilitation takes the most important, difficult and long stage.
An entire team of specialists helps the patient to go through the rehabilitation period, which includes otosurgeons, sound teachers, audiologists, psychologists. Classes are conducted according to special techniques and lengthy training sessions, as well as consultations of all these specialists. In the future, their observation is necessary throughout the life of the patient. In addition, the speech processor will need to be reprogrammed periodically.
Hearing Aids. Prices
For people with a low level of sound perception, many devices have been developed - hearing aids that can help adapt in a social environment. Hearing aids are behind-the- ear devices that are attached behind the auricle, and intra- ear devices - they are located in the patient’s ear canal and are made to order. Currently, there are also digital models on sale.
In addition, there are deep-channel hearing aids. They are located in the auditory canal, very small in size and almost invisible to others. But such devices are contraindicated in children under 12 years old.
The cost of hearing aids is different, but it is relatively small. This allows a large number of patients to use hearing aids. Prices are quite affordable. So, behind-the-ear models can be bought from 4.5 to 17 thousand rubles. Intra-ear instruments are a bit more expensive.
Hearing loss treatment
If there is hearing loss, treatment will depend on the reasons that caused it. Among the options are possible:
- Removing sulfuric cork - this is done by washing, sometimes using a special tool.
- The use of hearing aids. In addition to the behind-the-ear, intra-ear and deep channel, hearing aids can be used, mounted in a spectacle frame or pocket, as well as in the form of a headband and even in the form of earrings. Which one is suitable for a particular patient, an otolaryngologist will advise.
- Cochlear implants - they were discussed in this article.
Hearing loss prevention
Hearing loss can be caused by illness, work in a noisy environment, or prolonged exposure to a noisy place. Hearing may also decrease due to age-related changes.
If the work is associated with noisy production, it is recommended to use headphones or other devices to protect against loud sounds at the workplace, such as special ear plugs.
Regularly check your hearing for all people associated with prolonged exposure to a noisy place. This will help to detect hearing impairment at an early stage and take measures in time, thereby preventing further hearing loss and the development of hearing loss or deafness.
Avoid too loud noises during the holidays and do not listen to very loud music or at least periodically take breaks.