What is a cochlear implant? Cochlear implantation - the ability to restore hearing with the help of modern technologies Preparation before surgery.

Cochlear implantation has become a common procedure worldwide for the treatment of severe hearing disorders leading to profound sensorineural hearing loss. The decision to have a cochlear implant is made either by the patient himself or by the child's parents or guardians. The procedure, lasting 60-75 minutes, is well tolerated and is usually performed on an outpatient basis, both in adults and in children.

The device and principle of operation of the cochlear implant hearing aid

A cochlear implant is surgically placed under the skin behind the ear. The main parts of the device are divided into external - located on the surface of the skin, and internal - directly to the implant. The hardware structure of the external device includes:

1. One or more microphones that pick up sound from the environment.
2. speech processor, which selectively filters sound waves by prioritizing sound speech, breaks the sound into channels and sends electrical sound signals through a thin cable to the transmitter.
3. Transmitter- physically consists of several coils held in place with a magnet. The transmitter, located behind the outer ear, amplifies and transmits the processed audio signals through the skin to the internal device using electromagnetic induction.

The internal device consists of:

• A receiver and stimulator attached to the bone under the skin that convert the signals into electrical impulses and send them through an internal wire to the electrodes.
• An array of 22 electrodes connected to the cochlea inner ear, which send the received electrical impulses to the nerve of the scala tympani, and then directly to the brain through the auditory nervous system.

Today, there are several manufacturers of cochlear implants, and each of them produces devices with a different number of electrodes. The number of channels is not the main factor on the basis of which the manufacturer is selected, these settings do not determine the quality of the device. It should be noted that the signal processing software algorithm, as a rule, is unique for each manufacturer, is its intellectual property and is not subject to distribution.

A cochlear implant may help people who:

• There is moderate to profound hearing loss in both ears.
• Hearing loss in one ear, with normal hearing in the other ear.
• The use of hearing aids does not bring the desired effect.

Many patients undergo the installation of the device in both ears - bilateral cochlear implantation. This approach can improve the ability to identify direction sound waves to be recognized.

One cause of hearing loss may be physical or functional damage to the hair cells of the inner ear or cochlea. A cochlear implant allows sound waves of certain frequencies to be transmitted directly to the cochlear nerve, which makes it possible to distinguish sounds.

When is implant surgery indicated?

There are a number of factors that determine the success rate of expectations from the operation and the device itself. Cochlear Implant Centers nominate a patient on an individual basis and make sure to take into account the history of hearing loss with a reflection of the causes. In addition, the quality of residual hearing, speech recognition ability, general condition health, hereditary factors of deafness and more.

The main candidate for cochlear implantation may be a patient:

• Has moderate to severe sensorineural hearing loss in both ears.
• Which has a functioning auditory nerve.
• Who lived, at least for a short period of time, with a loss of at least 70 decibels of hearing loss.
• Has good speech, communication skills and, in the case of infants and young children, has a family whose members can work towards developing speech and language skills with the young child.
• Not using other types of hearing aids, including the latest FM systems.
• Has the opportunity to purchase the appropriate services, specialists that will be required after the installation of a cochlear implant, for example, a speech teacher. This is especially true for pediatric patients.

People with mild hearing loss are generally not candidates for cochlear implants. Their needs can often be met with hearing aids. Once the implant is in place, the sound waves will no longer be able to penetrate the ear canal and middle ear - they will be picked up by the microphone and sent through the device's speech processor to the implant's electrodes inside the cochlea. Since implantation is an invasive process, in any case it does not have an advantage over classical hearing devices if their use is effective. Thus, most candidates for implantation are characterized by the presence of a severe or deep form of sensorineural hearing loss.

The presence of auditory nerve fibers importance for the operation of the device. If they are damaged to the point where they cannot receive electrical impulses, the implant will not work.

Patients who have lost their hearing due to diseases such as CMV and meningitis form three different groups of potential cochlear implant users with different needs and outcomes. For those who are deaf from birth, cochlear implants are helpful in restoring some understanding of speech and other sounds. In patients with congenital hearing loss, such a hardware solution may be the only way to distinguish previously unfamiliar sounds.

For parents of children born deaf who want their children to grow up with good spoken language skills, a cochlear implant can be very effective tool. The brain develops after birth and adapts its sensory input function. The absence of this capability has functional consequences for the brain, and consequently, deaf children who receive cochlear implants in early age(less than 2 years) show better success than congenitally deaf patients receiving implants for the first time at a later age. However, the critical period for distinguishing auditory information does not end completely in adolescence.

Experts believe that there is a time window during which children can receive an implant and learn to speak. Between the ages of two and four, this ability decreases slightly. At nine years old, there is almost zero chance that they will be able to learn to speak correctly. Therefore, the sooner the device is installed, the better.

A separate group of applicants for implantation may include patients with hearing loss who already have developed skills or ability to speak. These representatives will significantly benefit from cochlear implantation. Young children under the age of five, in these cases, often perform excellently, since they have already learned how to form sounds, and it remains only to master the process of interpreting new information in the brain.

How effective is a cochlear implant over a conventional hearing aid?

A cochlear implant will not cure deafness, but it can provide hearing quality sufficient for speech and some audio frequencies. Some patients find them very effective, others not very effective, others feel worse overall with an implant than without it.

For people with developed functional speech, cochlear implants can be a great help in restoring functional speech understanding, especially if they have lost their hearing relatively recently.

Patients suffering from deaf-blindness experience a radical improvement in their daily lives. The implant can provide them with more detailed information on safety, communication with the outside world, balance, orientation and mobility, as well as facilitate their interaction in the environment and with other people, thereby reducing isolation.

Adults who grew up deaf may find implants ineffective or annoying. This refers to the specific pathology of hearing and the time of its absence. Adults who were born with normal hearing and those who had normal hearing at an early age show the best results. In children with auditory nerve damage, results may not be optimal.

It should be noted that a cochlear implant and a classic sound apparatus are devices with completely different approaches to providing auditory processes, so it is somewhat incorrect to compare them. The role of the hearing aid is only to amplify the surrounding sounds and transmit them to eardrum. For the functioning of this device, analog means of processing sound waves are sufficient. A cochlear implant is a small computer that operates in a digital environment and provides reception of a sound wave, converting it into electrical energy and transmission directly to the neural network of the inner ear.

Thus, the installation of an implant in the case of the possibility of functioning of the hearing aid is possible, but the reverse process, either physically or biologically, cannot be provided. Once again, it is worth emphasizing that if a hearing aid provides at least a slight improvement in the quality of hearing, then it is not recommended to change it without an implant - in any case, the effect will be lower.

Risks and disadvantages of implantation

Some of the effects of implantation are irreversible. While the device promises to provide new audio information, the implantation process inevitably destroys some of the hair cells inside the cochlea, which can lead to the permanent loss of all residual qualities of natural hearing. However, with the use of flexible electrodes and modern surgical methods, the vast majority of hair cells can be preserved. While recent improvements in implant technology and techniques promise to minimize such damage, the risk and extent of damage still fluctuate. The goal of the new implantation methods is to reduce the risk of infection, increase the device's operating time and eliminate complications while improving the patient's ability to hear in general.

The basis for improving implantation methods includes expanding the frequency range of sound waves that can be perceived and processed by a computer, and methods for protecting the device.

A significant disadvantage of cochlear implantation can be considered the impossibility exact definition causes of deafness before surgery. Apparently, for this reason, implantation does not help everyone.

In rare cases, there is tissue necrosis of the skin flaps surrounding cochlear implants. The use of hyperbaric oxygen has been shown to be a useful adjunct to therapy in the control of necrotic lesions.

Due to the anatomical proximity of the cochlea to the facial nerve, there is a risk of iatrogenic damage to the latter, including during operation.

There are strict protocols in the selection of candidates, which helps to avoid the risks and disadvantages of the procedure. A set of special tests is carried out to help decide on the need for surgery. For example, some patients suffer from deafness caused by cochlear pathologies such as vestibular schwannoma lesions. Implantation in this case has a low success rate - the artificial signal simply will not be able to favorably contact the auditory nerve.

Historically, patients with severe congenital cochlear anomalies have been considered poor candidates for cochlear implantation. Many studies, regularly conducted since 1980, have demonstrated successful results of implantation with the use of more advanced means of processing sound waves.

Implant placement technique

The device is implanted under general anesthesia or local anesthesia. The operation usually takes 1.5 to 5 hours. The first small area of ​​the scalp directly behind the ear should be shaved and aseptically cleaned. Then an incision is made and the internal block of the cochlear implant is inserted into the newly created pocket. After that, work is carried out in the inner ear, where many electrodes are connected to the cochlea.

The patient usually leaves on the same or next day after the operation, although some cases may require a hospital stay for 1-2 days.

Like any medical procedure, surgery involves a certain number of risks:

• Possible skin infection.
• The occurrence of tinnitus.
• Damage vestibular system and facial nerve, which can lead to muscle weakness, impaired sensitivity in the face.
• In the worst case, the operation may end with facial paralysis.
• There is also a risk of device failure, which occurs in 2% of cases, and the device must be removed.

There is also the potential for residual hearing loss due to damage to the hair cells in the cochlea, but it is worth emphasizing further that the chances of such complications are decreasing with more and more technological advances.

If the child wore hearing aids, then after the operation, he continues to wear the device on the non-implanted ear. After turning on the CI processor, the child should continue to wear the hearing aid with the CI. This provides binaural hearing, which improves the localization of sound in space, increases the noise immunity of speech perception in noise. In this case, it is necessary to reconfigure the hearing aid with the CI turned on according to the child's feelings (reducing the gain level, turning off high frequencies). It is also necessary to observe the mode of adaptation to the use of CI and a hearing aid. During the month, classes should be held only with CI. At the same time, the rest of the time the child should wear only CI (2/3) part of the time, and part of the time CI and a hearing aid. In some cases, this ratio may change. Later, the child constantly wears both devices, including in the classroom.

However, experience shows that many children soon refuse to wear a hearing aid. There are several factors that determine this. One of the main ones is the feeling of discomfort from a poorly made or inappropriate size due to the growth of the child's liner. The second factor is the small remnants of hearing on the non-implanted ear - in their complete absence, the use of a hearing aid is impractical. The third factor is the type of hearing aid used by the child - the sound from an analog hearing aid, especially a low-quality one, is very different from the signal transmitted by the CI. The sound transmitted by a high-quality digital apparatus is close to the signals transmitted by CI and is better integrated by the brain. Professionals and parents should make every effort to ensure that the child continues to wear a hearing aid with a CI.

CI models have now been developed that combine the use of a CI and a hearing aid in one ear. These models are designed for people with good low-frequency hearing remnants, providing them with the best perceived speech quality.

3.3. Hearing-speech rehabilitation of children with a cochlear implant who lost their hearing after mastering speech Restoration of hearing-speech perception

Since the language system and own speech are already formed in postlingual or late-deafened children, postoperative rehabilitation, in addition to setting up the CI processor, mainly includes the restoration of auditory perception of surrounding sounds and speech with CI.

The speech signals transmitted by CIs are significantly distorted and differ from those stored in the memory of a late deaf child. This determines the main objectives of the auditory training program:

To teach the child to find a correspondence between the sound images of speech sounds and words transmitted by CI with those stored in his memory;

To teach the child to distinguish in new images of speech sounds the acoustic correlates of the differential features of phonemes - “voicedness-deafness”, the place and method of articulation, etc.

Accumulate in the child's memory new sound images of speech sounds, words, phrases, environmental sounds,

Classes on the development of auditory-speech perception begin immediately after the first setting of CI. On the first day there are 2 lessons lasting 30 minutes. with a break of 2-4 hours to adapt and correct the settings of the speech processor. As our practice has shown, the optimal duration of the course of hearing and speech rehabilitation for PLP is 3-4 weeks. In the first two weeks, it is desirable to conduct 2 classes (45-60 minutes per day with different teachers, then 1-2 classes per day. During this period, it is possible to sufficiently restore auditory perception and achieve stable values ​​of the CI processor settings necessary for good intelligibility of perceived speech and its perception in various communicative situations, to correct existing speech disorders. with tinnitus, in which the ability to perceive speech is restored more slowly.

Training for the development of auditory perception with CI in PLP includes:

1. Training for the detection, discrimination and recognition of non-speech (everyday) sounds of the environment (tasks 1-6 are carried out from the 1st lesson).

2. Training to recognize words with different syllabic structures (one-, two-, three-syllable words, numbers) in a closed (limited) choice.

3. Training to distinguish between different signs of non-speech and speech sounds (number of sounds, long-short, loud-quiet).

4. Training to distinguish and recognize the sounds of musical instruments, sounding toys.

5. Training to distinguish and recognize isolated low- and high-frequency speech sounds (isolated phonemes [a], [i], [y], [s], [w], etc.).

6. Training in recognition of words with the same syllabic structure (three-, two-, or monosyllabic) and with different/same position of the stressed syllable (polysyllabic words) in closed choice.

7. Training for the perception of suprasegmental characteristics of speech signals (number of syllables, position of the stressed syllable, position of the highlighted word in the phrase, intonation of the sentence) (tasks 7-10 are carried out from the 2nd lesson).

8. Training to distinguish and recognize isolated vowels, as well as vowels in syllables of the SG type in the context of various consonants.

9. Training for word recognition in continuous speech with a closed choice.

10. Training for recognition of words with the same syllabic structure (three-, two- or monosyllabic), differing in vowels / consonants in a closed choice (from the 3rd lesson).

11. Training for distinguishing and recognizing isolated consonants, as well as consonants in syllables such as consonant-vowel, vowel-consonant-vowel (from the 3rd lesson).

12. Training for the recognition of words with different syllabic structures with an open choice (tasks 13-18 are carried out from the 4th lesson).

13. Training for the recognition of monosyllabic words with an open choice.

14. Training for distinguishing phonetic characteristics (vowel-consonant, sonority-deafness, place of formation, sonority, softness-hardness) in syllables and words.

15. Training to distinguish words in sentences with a well-predictable last word in an open choice.

16. Training for the perception of prosodic information in speech (interrogative / narrative / exclamatory intonation, position of semantic stress, emotional state of the speaker, identification of male and female voices)

17. Training in understanding familiar issues.

18. Training to distinguish words in sentences with a poorly predictable last word in an open choice (from the 7th lesson).

19. Training for the perception of continuous speech in a situation of open choice (from the 8th lesson).

20. Training in recognition of words with different syllabic structures (one-, two-, three-syllable) in a closed choice under conditions of external noise (20-25 tasks from the 10th to 40th lesson).

21. Training for recognition of words with the same syllabic structure (three-syllable, two-syllable, one-syllable) in closed choice in noise.

22. Training for word recognition in continuous speech (sentences) in closed choice in noise.

23. Training in understanding familiar questions in noises.

24. Training of perception of speech on the phone.

25. Training of sound source localization in space.

Restoration of auditory perception with the help of CI starts with simple tasks, moving successively to more complex ones.

The easiest task- is to detect if there is sound or not. In this task, the child is presented with different non-speech and speech sounds, of different loudness, frequency and from different distances. The child must say whether he hears this sound or not. He does not need to recognize this sound.

The second task in terms of difficulty- is the ability to distinguish between two sounds. To do this, the child is presented with two words (or two non-speech sounds, or two phonemes). The child must say what word he heard. The child can perform this task even if he learns only one word. For example, when the words “house” and “car” are presented, the child recognizes the word “car” well. When the word “house” is presented to him, he does not hear it clearly, but he definitely hears that it is not a “car” and answers correctly.

The third task in terms of difficulty- this is the ability to recognize sounds (non-speech and speech) in a situation of closed (limited) choice. In this situation, the child knows exactly which signals (words, syllables, sentences, phonemes, non-speech sounds) will be presented to him. At the same time, a list of these signals (or a set of pictures) lies on the table in front of the child. Answering, the child shows the heard word (sound, sentence, etc.) in the list in front of him or repeats it. In such tasks, the child can recognize the word, even if he does not hear it clearly, excluding those for which what he hears is unlike. At the same time, he should try to guess which word, from those lying in front of him in the list, the heard word looks like. The minimum number of signals that can be presented in this task is 3. An increase in the number of signals complicates the task.

Suggestions can be used as signals in this task. Compared to isolated words, this is a more difficult task, because at the initial stage, patients with CI analyze speech very slowly and do not have time to recognize words in continuous speech.

All these tasks begin with the presentation of auditory-visual signals - the child sees the face of the teacher, who indicates which word from the list he pronounces or sees objects that make sounds. After that, the signals (sounds, words, sentences) are presented only by ear.

In contrast, in open-choice tasks, the child does not know what kind of signals will be presented to him and cannot predict them. Therefore, he can rely only on his ability to hear. These tasks are carried out when the child performs the speech recognition tasks well enough in a closed choice of 10-12 words.

The first lesson begins with the restoration of the ability to detect various non-speech and speech sounds, identify the difference in their sound and identify them. For this purpose, the child is offered to listen to various everyday sounds, including non-speech sounds made by a person (steps, door creaking, strumming of a spoon in a glass, phone ringing, paper rustling, whistling, drumming, sound of a stream of water, coughing, blowing nose, etc. .), sounds of musical instruments (drum, pipe, whistle, rattle, xylophone, etc.). At the same time, real situations and objects are used with a preliminary attraction of the child's attention to the sound source.

In the same lesson, non-speech sounds, as well as speech sounds, are used to restore the ability to distinguish certain characteristics of sound signals: "loud-quiet", "one-many", "long-short", "high-low".

Speech perception training begins with distinguishing and recognizing isolated words and speech sounds in a closed choice situation. First, 3 words are presented. Previously, the child is presented with these signals auditory-visually - the child sees the face of the teacher, who indicates which word from the list he pronounces. If the child cannot recognize the word, you should ask him to try to guess which word of the words in front of him looks like the word he heard. Some children answer only when they are sure of the answer. And for the development of perception, it is important that they learn to make a decision about a signal (for example, a word) even in the presence of partial information. This is one of the basic principles of information processing in the brain. If the child learns all 3 words, the number of words is increased to 6, 9.12. The first words should also include the name of the child, the words "mother", "dad", "grandmother", the names of family members. Children, as a rule, are already able to cope with this task, and the realization that they already understand the words is very inspiring for them and their parents.

For the first 1-2 days, children may report that they hear speech with some delay. At the same time, they get the impression that the sound of the voice lags behind the articulation. Within 2-3 days, the child ceases to notice this discrepancy.

At the first lesson, it is also proposed to distinguish (when comparing in pairs) and recognize (when choosing from 3 or more) acoustically very different long speech sounds, for example, [a], [y], [w], [s]). They start with 2 signals, as the task is completed for different pairs of sounds, the number of signals is gradually increased.

In tasks with a closed choice in the first lessons, the speech material is first presented several times with visual reinforcement. Then the same task is performed without visual reinforcement only by ear. If the child makes mistakes, then it is necessary to return to the audio-visual method of presenting the material, and then continue without visual reinforcement. As the auditory-speech perception with CI is restored, the speech material can be presented immediately only by ear. First, the teacher pronounces the speech material at a slower pace and with clear articulation. Upon reaching a stable correct recognition of material spoken at a slow pace, the material is presented at a fast pace of pronunciation.

Each lesson should end with a task that the child is already doing well. This keeps him positive. This algorithm is used when working with different speech material. The teacher must first select speech material and have printed lists with a different number of signals of different types (isolated phonemes; groups of phonemes with common phonemic distinguishing features; syllables; words with different and the same syllabic structure; pairs of words that differ in one phoneme; monosyllabic words; sentences with good predictable and poorly predictable composition of words; questions; texts - Appendix 1).

When working with teenagers and children, it is very important to choose speech material that matches the age of the child and his interests. This material should also be diverse in terms of topics, linguistic composition, etc.

For homework, listening to songs that the child knew before hearing loss can also be recommended. Although CI distorts the melody of songs to a certain extent, their rhythmic pattern is accurately conveyed, and many children enjoy listening to their favorite songs and recognizing their lyrics.

In tasks with an open choice in the first lessons, an audio-visual method of presenting the material is also first used. Then the signals are presented only by ear. If the child does not understand the spoken word (or phrase), it is repeated. If he did not understand in this case, then he should explain to the child what was said by writing this word or showing the appropriate picture. After that, it is necessary to repeat this word again several times, so that the child perceives it only by ear. If the child named some other word instead of the one presented, then it is necessary to pronounce these two words in turn, giving the child the opportunity to compare the sound of these two words, to feel the difference in their sound.

When training the understanding of continuous speech, reading short entertaining texts (100-200 words) is used, while the student must repeat the sentences read by the teacher. If the student did not understand any word, then the teacher repeats the sentence or part of it, gives words - synonyms, etc., achieving recognition of this word by the child. If it is difficult to recognize a word, you can write it down and show it to your child. In this case, another approach can also be used: the child first reads the text on his own, and then the teacher presents sentences only by ear.

The most important role in restoring the perception of speech with the help of CI is played by classes to develop the ability to recognize individual speech sounds, because. this determines speech intelligibility. Due to the peculiarities of coding acoustic information of CI, individual speech sounds undergo significant changes. In order for the child to learn to recognize individual phonemes well, several types of exercises are used:

Distinguishing phonemes in paired comparison (with isolated presentation, as part of syllables surrounded by different sounds of speech, words). Start with vowels. (Attachment 1);

Recognition of phonemes when choosing from 3, 4, 5 or more (with isolated presentation, as part of syllables surrounded by different speech sounds);

Distinguishing and highlighting differential signs (voicing-deafness, softness-hardness, place of formation, vowel-consonant, nasal-non-nasal, etc.); This exercise is especially effective, because. contributes to the rapid development of the ability to distinguish individual phonemes. The greatest difficulty is the distinction between explosive consonants that differ in the place of formation /b-d-g/, /p-t-k/.

The ability to detect the presence or absence of a sound in a word and determine its position in the word;

Determining the correct and incorrect pronunciation of a phoneme in a word, etc. As a result, most children using CI with a fast coding strategy manage to achieve 90-95% of phonemic intelligibility in syllables.

Cochlear implants are usually performed in one ear. With such a monaural perception, the localization of sound in space is not an easy task for the PLP. To develop this ability, special classes are needed to localize the sources of non-speech signals and speech, which improves the child's orientation in space and adaptation in a changing acoustic environment. However, it should be borne in mind that even after training, the child's ability to determine the position of sound in space with one CI is limited, especially in the front-to-back direction and in noisy environments (outdoors, in a noisy room). As a rule, the child first detects the sound, begins to look for its source, turning his head in different directions, simultaneously identifies the sound image (for example, speech or car horn) and, first of all, determines from the situation where the sound signal comes from.

Since the speech signals transmitted by CIs are distorted, children take longer to process them. Therefore, children with CI, especially in the first year of using CI, are much slower to understand what was said, they need to repeat it several times before they understand what they hear. In this regard, in the process of auditory-speech work with a child, it is necessary to present speech material (words, phrases) for identification, pronouncing it at different speeds - first a little slower, with clear articulation, and then, after the child has exactly repeated what he heard - in a faster pace.

It is also necessary to conduct exercises to develop the ability to distinguish people's voices. At first, the voices of different people sound the same to the child, but gradually this skill develops, although he will do it worse than a normal hearing child. It is better to start with the fact that, when presenting speech material to a child, it is sometimes necessary to pronounce words in a higher or lower voice. The child should at the same time note a change in the pitch of the voice. Parents can also be involved in this exercise. Together with the teacher, they pronounce words or sentences (already worked out) in turn in a random order, and the child must find out who said it. Audio recordings with male, female, children's voices are also used. Parents conduct such exercises at home. In the process of these classes, the child recovers the ability to distinguish male-female-children's voices, the ability to distinguish between familiar voices. This ability is also important for the perception of the speech of one speaker against the background of several speaking people.

To train speech perception against the background of noise, you can use audio recordings with noisy speech material, speech perception against the background of music or the radio on, as well as talking on the phone. At the same time, one should also start with perception in a situation of a closed (limited) list, i.e. when the child knows exactly what signals will be presented to him (when talking on the phone, you need to write the text of the dialogue in advance). Training in speech perception in noise is an important stage of work, since PLPs have difficulty understanding in noisy environments even after wearing a CI for a long time. This is due to less information redundancy and, accordingly, the noise immunity of speech signals transmitted by CI, as well as a violation of the central auditory processes in a part of the PLP. In the course of such classes, the problems of speech perception in noisy conditions are discussed with the child and parents, methods of successful implementation of communication using alternative strategies that contribute to the psychological stabilization of the child in difficult situations.

It should be remembered that the process of listening and perceiving speech with CI requires a lot of tension and energy from the child. In addition, many children who have lost their hearing after neuroinfections have various neurological disorders (asthenia of the nervous system), central hearing disorders (impaired auditory memory, attention). Therefore, at first, children in the classroom quickly get tired. In this regard, in the course of the lesson, it is important to intersperse auditory and speech work with other types of correctional work, which rely more on other analyzers.

As a rule, after 3-4 weeks of intensive training in the development of speech perception with CI at the center of cochlear implantation, late-deafened children understand speech in most communicative situations. However, their speech processing speed with CI is still insufficient, and the child needs to continue classes with a deaf teacher at the place of residence 1-2 times a week for several months. The child also needs additional Russian language classes. At the same time, throughout the entire process of auditory-speech rehabilitation, the child's parents are actively involved in the process of auditory-speech rehabilitation - they daily work with the child on the instructions of the deaf teacher.

Hearing loss or total loss leads to many difficulties in everyday life. Hearing aids were invented to solve the problems of hearing-impaired people. Cochlear is the most effective option.

Cochlear implant: what is it and how does it work?

People who have lost their hearing or suffer from congenital hearing loss are recommended to use cochlear implants. These high-tech electronic devices provide enhanced sound perception and recognition of human speech.

A cochlear implant, unlike conventional hearing aids, does not simply amplify sound, but is used as a complete replacement for the affected area of ​​the auditory organ.

The applied technique of electrical impulses allows you to directly deliver sounds to the auditory nerves.

The system includes several components:

• implant - a prosthesis that is inserted into the patient by a subcutaneous method;
• electrode array - a chain of electrodes that is inserted into the cochlea by a surgical operation;
• speech processor, consisting of a microphone, a microprocessor and a transmitter;
• compartments for accumulators or batteries.

Some models are equipped with remote controls and other optional accessories.

1. to get into the cochlea, the doctor makes a small incision behind the ear, and then a hole in the bone. An electrode is inserted through this hole, the task of which is to transmit sounds to the auditory nerve. A receiver is placed on the bone above the ear, to which the electrode is connected. After that, neat stitches close the incision;
2. dressings are made for 7-10 days, after which the stitches are removed;
3. when the operated area is completely healed (after approximately 4-6 weeks), the doctor connects the speech processor and transmitter.

Rehabilitation process after surgery

A necessary step is rehabilitation after surgery. During this long and responsible process, a whole team of professionals is actively working with the patient - otosurgeons, psychologists, audiologists and deaf teachers.

In order to improve the effectiveness of a cochlear implant, the patient must undergo special training. As a result, he will be able to identify sounds with maximum accuracy, expand speech skills and read lips.

The presence of a prosthesis does not affect the daily activities of a person, with the exception that it is contraindicated for him to engage in traumatic sports where blows to the head are likely.

Rules for the operation and repair of devices

The warranty on the inside of a cochlear implant is 10 years, although the device could theoretically function for life.

1. it is not advisable to work near devices and installations that are characterized by strong radiation. They can disable the processor software;
2. it is strictly forbidden to undergo MRI, MRI, NTR procedures without prior consultation with a doctor;
3. do not open the processor case (this can lead to damage and void the warranty);
4. before turning on the speech processor, make sure that there are no mechanical damages;
5. all components must be protected from bumps and falls;
6. the temperature regime of the speech processor is from -10 to +45 degrees.

Every cochlear implant recipient is recommended to have their speech processor replaced once every five years. This procedure is designed to maintain high sound quality. To do this, you should contact the medical center where the primary installation and adjustment of the cochlear implant was carried out.

After connecting a new processor and transferring the settings from the previous instance, the patient is hospitalized for 2-3 days to make sure that the replacement was successful and that he hears normally without experiencing discomfort.

The cochlear implant owner can replace the batteries themselves. For this you need:

1. carefully slide the battery cover of the sound processor down and remove it after a characteristic click;
2. lift the inner sash with your fingernail to open access to the battery;
3. remove the battery and dispose of;
4. on the side of the positive contact of the new battery, carefully remove the sticker and insert it, pointing to the “+” sign on the compartment;
5. close the inner flap, and then replace the battery cover.

Well-known companies producing new generation devices for children and adults

To do right choice cochlear implant, you should get acquainted with the most famous and prestigious companies involved in the production of these devices.

Kohler (Cochlear)

Cochlear is a leading manufacturer of next generation high quality cochlear implants. It was founded in the 80s of the 20th century in Australia. Distinctive properties of the devices of this company are safety, reliability and comfort.

Implant Kohler, working in conjunction with the phone

The company's portfolio includes Nucleus® Cochlear Implants, Cochlear™ Acoustic Devices, True Wireless™ Devices, Baha® Bone Implants and Vistafix® Bone Prostheses.

In Russia, these cochlear implants can be purchased from Euromax, which is an official Cochlear dealer.

Neurolec (MHM Neurelec)

The French company Neurelec (MHM Neurelec) has been producing cochlear prostheses since 1977.

The main advantages of the Digisonic SP implant are:

• convex shape of the ceramic case with silicone for high strength;
• facilitated the process of introducing the prosthesis into the cochlea due to specialized electrodes;
• minimizing the risk of complications due to the fixation of the implant receiver with two screws.

Implant Digisonic SP

Medel (Med'El)

Med'El has been manufacturing high quality hearing aids for over thirty years. All its devices are characterized by high performance, reliability and ease of use. The range of this company includes such high-tech systems as MAESTRO, EAS, VIBRANT SOUNDBRIDGE, BONEBRIDGE and ADHEAR.

Bayoniks (Advanced Bionics)

Advanced Bionics is a leading manufacturer of cochlear implants for adults and children. Harmony's unique HiResolution Bionic Ear System technology maximizes the effect of sound perception and allows you to correctly navigate in complex sound environments.

Implant Bayoniks

Anjoy (iEnjoy Sound)

The South Korean company Enjoy (iEnjoy Sound) is a promising manufacturer of cochlear implants that combine reliability, convenience and reasonable cost.

Nuroton (Nurotron)

Nurotron is a Chinese company that has been manufacturing the efficient and reliable Nurotron® Venus cochlear system since 2006. The advantages of this electronic device are slim and ergonomic body, soft design of platinum electrodes, targeted stimulation of spiral ganglion cells.

Nurotron Venus System

Prices for cochlear implants and accessories

The cost of cochlear implantation includes preoperative diagnosis, the operation itself and postoperative correction. On average, it is 1,200,000 - 1,300,000 rubles.

The price of batteries varies from 13,000 to 17,000 rubles, coils - from 12,000 to 20,000 rubles, controllers for speech processors - from 50,000 to 69,000 rubles, battery holders - 4000-6000 rubles.

Cochlear implantation is a procedure that is faced by people who have lost their hearing for one reason or another. Given that, according to statistics, about 12 million people in Russia have problems of this kind, this manipulation is quite common.

Usually, most patients have hearing aids installed if necessary. But if these devices do not give the expected result, then experts suggest installing a cochlear implant to improve hearing. Whom and in what situations can this procedure help and what are the risks during installation?

Indications for installation

Modern medicine does not stand still, and cochlear implants have been invented for people with reduced or absent hearing.

They are shown in the following cases:

• if the patient has deep sensorineural (neurosensory) deafness;
• if after binaural prosthetics the patient has low threshold perception of sounds;
• at total absence speech perception in conditions of an optimally selected hearing aid (if the situation lasts about 3 months);
• when diagnosing a patient with deep bilateral sensorineural hearing loss.

Cochlear implant placement is possible if:

• the patient does not have cognitive problems (mental disorders) of various etiologies;
• the person does not suffer from mental illness;
• diagnosis did not reveal somatic ailments.

Contraindications

Cochlear implantation solves the problem of people suffering from hearing problems, but there are situations when the operation can be harmful. The installation of implants will not help to achieve the desired result in the following situations:

1. If hearing loss occurred due to neuritis (inflammation) of the auditory nerve, cerebral hemorrhage (temporal, stem lobes).
2. With calcification (calcium salt deposits) of the cochlea.
3. With ossification, that is, the process of germination of the bone tissue of the cochlea.
4. If patients have been in absolute silence for a long time, then irreversible atrophy of the branch of the auditory nerve occurs, and it is useless to perform cochlear implantation.

Contraindications include the following conditions:

• inflammation of the middle ear;
• perforation (rupture of the film) of the eardrum;
• hair cells are preserved and are in working condition (examined by the method of otoacoustic emission).

Cochlear implantation in children is not performed if the child is older than 6 years and diagnosed with prelingual deafness.

Besides, this species operations are not done in the case of postlingual deafness, which lasts longer than the period of normal auditory functions.

Possible postoperative complications

Cochlear implantation is surgical intervention, moreover, it affects an area close to the brain, so there are still risks of complications, although rare. These include the following states:

• damage to the facial nerve (paresis) or its paralysis on the side of the face that underwent surgery;
• dysfunction of taste buds;
• disruptions in the activity of the vestibular apparatus (the patient may periodically feel dizzy, lose stability when walking, nausea with vomiting);
• after surgery, headaches, tinnitus (ringing and noise in the ears) are possible;
• processes of ossification or calcification of the cochlea with the implant.

Cochlear Implant Components and Functions

This type of hearing implant consists of 2 parts that do not have any physical connections between them.

One of the parts is attached behind the ear from the outside. Its components are a microphone, a processor (newer models of implants are produced with these components combined), as well as a transmitter, the attachment of which to the skin resembles a magnet.

There is also an inner part, which is the receiver. During the operation, it is fixed into the temporal bone, this is the answer to the question of what cochlear implantation is.

The structure works like this:

1. A microphone attached to the outer ear picks up sounds and sends them to the speech processor.
2. The processor, in turn, encodes sounds and converts them into electrical impulses.
3. Using a transmitter located on the skin, the impulses are delivered to a receiver located in the temporal bone.
4. From here, they enter the cochlea through the electrode and affect certain parts of the auditory nerve.

This whole cycle, which is carried out by the cochlear implant, allows the patient to perceive sounds.

Preoperative examination

This process largely depends on how the patient feels and what is the history of his diseases. For example, if a person has been diagnosed with meningitis, then as additional measures he is prescribed an MRI (magnetic resonance imaging), which determines the condition of the bones of the temporal part of the skull. Other patients do not need this procedure.

Often, but not necessarily, the patient is advised to consult a geneticist, a neurologist before an operation is scheduled.

The required activities include the following:

1. Examinations and consultations with specialists: otolaryngologist, otoneurologist, deaf teacher.
2. Carrying out some measurements and finding out the condition of the ear: audiometry (measurement of hearing acuity); impedancemetry (diagnosis of the state of the middle ear); promontory testing (checking the condition of the auditory nerve); otoacoustic emission (method of testing hearing in a patient).
3. Acoustic auditory evoked potentials (diagnosing to assess the level and quality of sounds received by the subcortex of the brain).
4. Computed tomography of the temporal lobe bone.

To put a cochlear implant, you will have to pass the tests necessary for any surgical intervention - general analysis urine, biochemistry and complete blood count, blood test for glucose levels.

Recovery after surgery

The surgical intervention lasts about 90 minutes, during which time the implant is attached to the temporal bone in the behind-the-ear region, and the electrodes are placed in the cochlea.

Sometimes the operation involves the installation of independent designs of devices on both ears, and this is done at the same time. Then 1-1.5 weeks are given for recovery, during which the patient visits the dressing room, and upon completion, the stitches are removed.

The system can be turned on only after 3-4 weeks, sometimes later. This moment requires increased accuracy so that the patient is ready to return to the world of sound and does not get stressed.

After a cochlear implant has been placed, the patient needs rehabilitation. A person must learn how to use a speech processor, which, in turn, needs qualified tuning.

This stage is long, laborious, and specialists from various areas medicine - otosurgeons, audiologists, teachers of sign language translation. Often people need the help of a psychologist.

Rehabilitation is carried out according to specially developed methods and is constantly accompanied by consultations with doctors. The people to whom the device was installed are observed for life in medical centers and regularly undergo scheduled diagnostics.

In addition, patients should be warned that the cochlear implant needs regular reprogramming.

The procedure for implanting ear implants is a relatively new technique and has already managed to establish itself as a good way to restore people's hearing. Whether cochlear implantation is suitable for a particular pathology, only a doctor can decide after careful diagnostic measures.

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

Hearing-impaired children have a poor understanding of speech and other sounds. They hear them as quiet, unintelligible. In most cases, they are assisted by a hearing aid that amplifies sounds (Fig. 1). However, if a child has severely damaged or lost hair cells, a hearing aid may not help. In such cases, hair cells cannot convert even amplified sounds into electrical signals, which is necessary for the perception of sounds by the brain. But a cochlear implant can do that.

CI is essentially a type of hearing aid. Its difference is that it does not amplify sound, but replaces the hair cells of the inner ear and transmits sounds and speech with the help of weak electrical discharges directly to the auditory nerve (Fig. 1). The use of CI is based on the fact that with sensorineural hearing loss, the cochlear receptors are usually affected, and the fibers of the auditory nerve remain unharmed for a long time. CI makes it possible to perceive high-pitched sounds well, which children with severe hearing loss do not hear or hear poorly even with powerful hearing aids.

The outer part of the CI includes a microphone and a speech processor placed in a housing resembling a behind-the-ear hearing aid, as well as a transmitter with an antenna. The transmitter is worn behind the ear under the hair. It is attracted to the implanted part through the skin with a magnet. The speech processor is the main and most complex part of CI. It is a small powerful computer. On the outer part of the CI there are controls that allow you to adjust the volume of sounds, select a program for processing them, etc. There are also indicators that control its operation, including a low battery indicator (usually light and sound). In addition, various external devices can be connected to it - a TV, telephone, etc. In a cochlear implant OPUS 2 regulators are located in the remote control, like a TV.

CI is powered by rechargeable batteries or disposable batteries. Disposable batteries usually provide enough power for several days of CI operation.

The interior of the CI is designed for lifetime use. CIs are designed in such a way that when creating new, more advanced models, it is possible to replace the outer part of the CI with a new one without a second operation. In many previously implanted patients, the pocket CI processor has been replaced with a behind-the-ear model. New models of the internal implantable part are also being developed. They are installed in patients who have recently applied for help.

CI models from different manufacturers differ in the number of electrodes, speech signal processing strategies, and a number of other technical data. Speech processing strategies are the main characteristics of CI that determine the intelligibility of perceived speech. The number of electrodes in different CI models ranges from 8 to 24. Each electrode transmits information about a certain range of sound frequencies. Studies have shown that 8 channels are sufficient for speech transmission.

CI manufacturers are constantly improving them, improving various parameters: the quality of speech perception in silence and noise, dimensions, etc. Various modifications of electrodes (shortened, split) have been created. They are intended for children with partial ossification (after meningitis) or cochlear anomaly who cannot insert a standard length electrode. The shortened electrode is also used for implantation in people with good hearing in the low frequency range. At the same time, CI transmits information about high frequencies of speech, and a person perceives low frequencies with the help of a hearing aid on the same ear. Studies have shown that speech sounds more natural and intelligible.

A fully implanted CI model is being developed. At present, the main problem in creating such a CI is the lack of batteries that can ensure its operation.

To restore hearing in people with damaged auditory nerves who cannot be helped by a cochlear implant, a brainstem implant has been created. It is implanted in the cochlear nuclei of the brainstem during a neurosurgical operation. Such an implant in the world is used by several hundred people.

How does a cochlear implant work?

· Sounds are first picked up by a microphone.

· The signal from the microphone is then sent to the speech processor.

· The speech processor converts sounds into an encoded signal, which consists of successive electrical impulses.

· The encoded signal is transmitted via cable to the transmitter.

· The transmitter sends a coded signal in the form of radio signals through the scalp to a receiver under the skin.

· The implanted receiver decodes the signal and sends it as electrical signals to electrodes in the cochlea.

· Weak electrical signals transmitted by the electrodes stimulate the auditory nerve. In response, the auditory nerve transmits nerve impulses to the brain, which perceives them as sounds and speech.

"Cochlear Implantation and Children"