Subjective hearing research methods. Methodik
I Group exploration with live speech. This method is very valuable, since it allows you to determine the hearing acuteness and speech intelligibility. Quality data is interested in the patient first of all. For at least they are interested in the researchers, since they have social significance, determine the patient's professional suitability, the possibility of its contact with others, serve as an indicator of the effectiveness of the treatment methods and criterion for the selection of hearing aids, are the main feature for judgment about the degree of hearing damage in labor, military and forensic examinations. Rumors are examined by a whisper and colloquial speech. At the same time, a set of two-digit numbers and words from Table V. I. Voyacheki with a bass or distant phoneme in it are used. The speech's hearing study is the simplest method that do not require yritors or equipment, but giving certain information to judge the level of damage to the auditory analyzer. So, if the whisper speech is perceived very badly ^ ( own sink), and the colloquial is good enough, from a distance of 4-5 cm, that is, the bases to assume the defeat of the sound-by-obstinate apparatus; If simple sounds are numbers and single-sided words - the patient distinguishes well, and the phrases from the same distance does not understand, this may indicate a pathological process in the field of hearing centers.
II G P U P P A - Hearing Study using tubren (tuning audiometry). This simple tool method Known more than 100 years. There are various sets of chainboard, consisting of 3 tuningtones (128, 1024, 2048 Hz), and large-of-5,7 and even 9 tuningtones (16, 32, 64, 128, 356, 512, 1024, 2048, 4096 Hz ). The letters of the Latin alphabet use the letters of the Latin alphabet. Tamartal audiometry allows you to judge the nature of the auditory of the hearing function, that is, on whether the sound-conducting or sound pending device is affected by this patient. Tamertons explore the ERWS and bone conductivity, Weber, Rinne, Schwabach, Federichi, Zhele, and on the basis of them, make a preliminary conclusion about the nature of the hearing loss - bass, or discovers. III troupe - a study of hearing with the help of electro-acoustic equipment (electric audiometry). There are a tonal audiometry (threshold and outgoing), speech audiometry, determination of hearing sensitivity to ultrasounds, to high tones of the audible frequency range (above 8 kHz), detecting the lower boundary of the perceived sound frequencies. All these methods are subjective to subjective adulterness, i.e. The ideas about the audience function depend not only on its true state and used to explore the equipment, but also from the ability to understand, respond and respond to the submitted signals. In addition to subjective Audiometry, there is an objective audiometry. In this case, the answers do not depend on the desire or will of the surveyed. This is very important when studying hearing in young children, in military medical and forensic medical examination. An objective audiometry that allows you to accommodate the fact of the presence or absence of hearing, as well as clarify the nature of his violation, we will look at a little later.
As for such audiometric methods, such as a tonal threshold, speech audiometry, determination of the hearing sensitivity in the extended frequency range and to ultrasound, they make it possible to establish not only the character of the lesion of the hearing function, but also its localization: the receptor in the snail, the nerve barrel, the nuclei , subcortical and cortical
Audiometry is carried out with the help of special electronic devices, reproducing oscillations of a certain frequency and intensity, and converting devices - telephones, air and bone.
The results of the study of hearing with tonal threshold aduometry are recorded on special bookcases - audiograms. They have a zero level - the threshold of the hearing sensitivity is normal, on the abscissa axis, the frequencies on which hearing-of 125 Hz is investigated to 8 kHz, and on the axis of the ordinate - a decrease in hearing in dB. In most audiometers, the maximum intensity of the audio signal with air conduction is 100-110 dB, with a bone-60-70 dB over the zero level. The following tests of an outporn audiometry are most common: the definition of a differential threshold of the perception of sound force, the time of direct and reverse hearing adaptation, auditory discomfort and the sensitivity index to the short increasing sound. Refine the nature and localization of the lesion of the auditory analyzer to a certain extent helps an audiometric study of noise in the ears (if it is in a patient). On the audiogram, you can see the graphical registration of subjective noise in the ears studied by the overlap. At the same time, the intensity of noise in dB and its spectrum, i.e., the frequency response is established. Usually, when the sound-conducting apparatus is damaged, the noise is low-frequency, and with a lesion of the sound-sensitive - high-frequency. In our department, there are many years in detail the pathological auditory sensations, i.e., the noise in the ears, with different pathologies, but mainly with non-negative diseases of the ear. Research results help hold differential diagnosis, specify the testimony for the operation and choose the side of the operation, for example, with otosclerosis, painful noise in the ears in which it is often more worried about the patients. Electro-acoustic study of noise in the ears serves as a control over the effectiveness of treatment - surgical and conservative, including various types of reflexotherapy. The results of observations on the study of noise in the ears in a significant number of patients (more than 4,000) allowed us to summarize this material and present it in the form of a monograph.
For speech audiometry, a tape recorder is used to which an additional device is adapted to change the intensity of the speech reproducible in certain limits. At the same time, they use the standard speech of one person who are read in the words of 10 -3-10 * 6 times in each, with the same volume. In one group, words are dominated with medium and high frequency phones, in the other - low. As a rule, at speech audiometry, the threshold of 50% of the intelligibility and the level of 100% of speech intelligibility are determined. Since it is measured by the percentage of speech intelligibility at different levels of its intensity, speech audiometry also relates to the ongoing samples. When conducting speech audiometry, also constitute an audiogram. In people with a hearing impairment due to the damage to the sound-conducting apparatus, the increase in speech integrity curve repeats the curve in the form of normally hear, but it is right away, that is, towards large intensities. Under the defeat of the sound-visible apparatus, the curve of the speech intelligibility is not parallel to the normal curve - it is abruptly deflected to the right, it does not reaches the level of 100%. With an increase in the intensity of the transmitted speech, the intelligibility may even decrease. The study of auditory sensitivity to ultrasound is widely used in the last 15-20 years. This is a very informative method that allows you to determine the nature and level of damage to the auditory analyzer (according to the values \u200b\u200bof the thresholds in bone conducting judge the perception of ultrasounds with a frequency of up to 200 kHz and the phenomenon of their lacycling). There is an objective audiometry. This is primarily about the registration of auditory cortical and stem caused by potentials. The fact is that the sound signals affect the spontaneous electrical activity of the brain, that is, on activity that exists independently of external stimuli and reflects on the electroencephalogram with certain curves. These curves are characterized by amplitude and frequency. The parameters of the electroencephalogram change when sounding sounds. However, attempts to use changes in the parameters of the electroencephalogram to establish the state of hearing were not crowned with success and did not find applications in audiological practice, although they have great importance For physiological research. Modern electrophysiological evaluation of hearing in clinical audiology is based on the registration of potentials in separate areas of the brain (bark, brain barrel) in response to the action of the sound signal. Therefore, such potentials were called auditory caused potentials. Typically, the auditory caused potentials are discharged from the region of the topping point of the pattern - VERTEX. To reproduce the caused potentials, sound signals of a small duration-click, which do not have a tone painting, and longer sound pulses containing the tones of different frequencies. In order to evaluate the results of the study using a computer, it is necessary first of all averaged potentials caused, so such a study received the name of computer audiometry. The computer audiometry method is complicated - the limited tasks for which it is intended, makes it necessary to organize such studies in special centers or institutions. However, the development of this method should lead to the development of a physiologically substantiated and reliable method of an objective evaluation of hearing.
One of the methods of an objective evaluation of hearing is the impedance thympa-and reflexometry. The method is based on the registration of acoustic impedance, or resistance, which meets the sound wave on the path of distribution over the acoustic system of external, middle and internal ear. The predominant value of the impedanceometry has to assess the state of the middle ear structures. The assessment is made according to the title analyzing, which graphically presents the dynamics of acoustic impedance in the process of artificially created air pressure drop in the outer hearing aisle within ± 200 mm of water. Art.
Iv Group study of hearing with unconditional and conditional reflexes on sound.
Of the unconditional reflexes, first of all, you need to name two - auropalpal and auropillar, respectively, blinning and pupil reactions to the sound. The unconditional response to the sound occurs from the child from the first hours after birth. However, it is indicative, and consequently, unstable, low-sensitive and quickly fading. But to solve the question in general form On the presence or absence of hearing in a child, auropalfebral and auropillar reflexes help. It is only necessary to exclude the element of tactile irritation in the study, i.e., the sound of the ratchet of the Barani or the tuningtones, and not cotton in your hands.
2. The core of the vestibular analyzer and their connection with other departments
central nervous system.
3. Nose partition, its deformation; Indications and types of operations on
Nose partition.
The curvature of the nasal partition is one of the most frequent rinological pathologies. In literature, it is found in 95% of people. The causes of such frequent deformation may be anomalies (variations) of the facial skeleton, rickets, injuries, etc. due to the fact that the nasal partition consists of various cartilage and bone structures limited from above and below with other elements of the facial skull, the perfect and combined development of all These components are extremely rare, it is the inconsistent pace of development of the facial skeleton and determine one of the main reasons for its deformation.
Variations of septal septum are very different. Displacements are possible in one direction or the other, S-shaped curvature, the formation of ridges and spikes, the sublinks of the front department of quadrangular cartilage. Most often, the deformation is observed in the junction of individual bones and quadrangular cartilage. Especially noticeable curvatures are formed in places of compound of quadrangular cartilage with a soul and perpendicular plate of the lattice bone. It is necessary to recall that quadrangular cartilage often has an elongated sphenoid outflow, heading by the post, towards the wedge-shaped bone. The formed deformations may be in the form of long formations in the form of ridges or short in the form of spikes. The compounds of the coupling compound with the scallop, formed at the bottom of the nasal cavity by the chival proceedings of both upper jaws, is also a favorite localization of deformations. It is impossible not to mention the insidious union of the nasal partition, which practical loros doctors are often underestimated. Such is the curvature of quadrangular cartilage in the anterior-upper part of it, which does not interfere with the ferris of most of the nose cavity and even the rear wall of the nasopharynx. However, it is this variation of the curvature of the nasal partition that may cause breathing difficulty. The latter is due to the fact that the inhaled jet of air, having, as you know, not the sagittal direction in front of the back, but forming a convex upward arc, finds an obstacle to my movement in this place.
The deformation of the nasal partition, causing a violation of the function of external respiration, determines a number of physiological deviations that mentioned when considering the function of the nose.
In the nasal cavity itself, the breathing defects reduce the gas exchange of the incomplete sinuses, contributing to the development of sinusits, and the difficulty of entering the air in the olfactory gap causes a violation of the smell. The pressure of the ridges and spikes on the mucous membrane of the nose can lead to the development of vasomotor rhinitis, bronchial asthma and other reflex disorders (Voyachek V.I., 1953; Dajnak L.B., 1994).
Clinic and symptoms. The most important symptom of the clinically significant curvature of the nasal partition is one- or bilateral difficulty of nasal breathing. Other symptoms may be a violation of the sense of smell, benxability, frequent and persistent rhines.
Diagnosis. It is established on the basis of the aggregate assessment of the state of the nasal respiration and the results of rhinoscopy. It should be added that the curvature of the nasal partition is often combined with the deformation of the external nose of congenital or acquired (usually traumatic) genesis.
Treatment. Only surgical is possible. Indication to the operation is difficult nasal breathing Through one or both half of the nose. Operations on the nasal partition are carried out and as a preliminary stage preceding by another operational interventions or conservative methods of treatment (for example, to eliminate the ridge or spike interfering catheterization hearing pipe).
Operations on the nasal partition are carried out under local or general anesthesia. They are technically complex manipulations. Damage to the mucous membrane on the adjacent sections of the partition leads to the formation of persistent, practically unstopposed perforations. At the edges of the latter, bloody crusts breathe. Large perforations contribute to the development of atrophic processes, small cause "punching" when breathing.
IN AND. Warhead offered a generalizing name to all operations on the nasal nasal partition "Septum-Operation". In recent years, the term "septoplasty" is becoming popular.
Among the various modifications of septum operations, two methods fundamentally different from each other should be distinguished. The first is a radical subflashy resection of a nasal septum on Killian, the second is a conservative septum-operation of a warhead. At the first method, the sublifting (at the same time subdigar and expanded) is removed by most of the cartilage and bone island of the partition. The advantage of this operation is its comparative simplicity and speed of execution. Disadvantage - observed during breathing flotation of the nasal partition, devoid of most of the bone-cartridge-throes, as well as a tendency to the development of atrophic processes. In the second method, only those sections of the cartilage and bone island are removed, which cannot be redesigned and put into the correct median position. When the quadrangular cartilage is curved, the disk is cut through circular resection. As a result, the disc, which retains communication with the mucous membrane of one of the parties and acquired mobility is set to the median position.
With very pronounced quadrangular cartilage curvatures, it can be dissected to a greater number of fragments, also retaining communication with the mucous membrane of one of the parties.
Conservative methods of operation on the nasal partition - more complex interference in surgical terms. However, their large duration and possible moderate reactive phenomena in the nasal cavity in the first weeks after the operation are currently paying off by the preservation of the almost complete nasal partition.
4. Professional selection for the auditory and vestibular function, its
value for different species aviation, including space and
Sea fleet.
It lies in determining the shelf life to one or another type of labor, a profession. Based on the data on the structure and function of the DPI and the ear, the question is solved in what production a person can work, in what - it is, suitability for service in the aircraft or in a certain kind of troops. Prof.Tebor is carried out by identifying indications that should reflect the actual impossibility of performing specific labor in connection with a certain state of health. Taking into account the state of health, the Council is given to the selection of the most appropriate type of employment, thereby implementing professional advice.
To clarify the hearing in violation of sound driving, especially in children aged 1 to 3 years apply objective electrophysiological methods. In particular measurement acoustic impedance, or measure the resistance of the sound wave in sound conductive hearing system. Well-hearing children, the sound wave freely enters interior Ear, acoustic impedance equals zero.
If the function is violated drumpatch, auditory bones, hearing pipes, windows of the labyrinth, the sound wave is experiencing resistance when passing into the inner ear, and it is reflected, with which the violation of the acoustic impedance is connected. Violations of acoustic impedance are recorded using a special device of the impedanceter, the sensor of which is entered into the outer hearing pass, and the sound of constant frequency and intensity is supplied. The results of the reflection of the sound wave are recorded in the form of curves that have different configurations depending on the detected pathology.
The objective electrophysiological methods include the method definitions of auditory caused potentials With the help of computer audiometry.
During the study of the electric potentials of the brain - electroencephalography, it has long been noticed that the sound irritation causes the appearance of electrical potentials that were named caused by auditory potentials. Subsequently, the potentials were differentiated different levels The auditory system: snails, spiral ganglium, brain cores, cortex of temporal brain lobe. Depending on the deadlines, they were divided on shortwavecoming from snail middle-wavegenerated in the stem structures of the brain and longwalle, emanating from the most remote departments, from the bark of the temporal lobe of the brain.
The discharge of electric potential from the snail, spiral ganglium is due to the need to summarize the electrode on the inner surface of the eardrum, so the testimony is limited to the presence of a drumpressing perforation or examination at 7 to 8 years under anesthesia, and later under local anesthesia, which is too hard for a child.
Conducting an examination with sound incentives, which are supplied to the outer hearing pass in the form of a click, register the small amplitude of the angry potentials caused, which are difficult to differentiate. With the help of computer equipment, the caused potentials are combined, and the overall result gives an average idea of \u200b\u200bthe hearing function.
Opening audiometry.
Opening audiometry This is a study of hearing when the sound in the ear is in excess of the hearing perception threshold from the surveyed. Such a study is carried out to clarify the place of hearing damage in the audio-visible hearing system, for example, to clarify the defeat of the spiral organic cells or hearing nerve.
The examination is based on purely clinical observation, namely, some of the hearing impaired people appear an unpleasant feeling in a sick ear, if they speak very loudly. This inexplicable increase in volume sensation has formed the basis of the outporn audiometry and got the name phenomenon of Accelerated Volume Ratings (Fung) in the terminology of Russian researchers and recruitment phenomenon In the terminology of foreign researchers. It is especially easily detected in people with a unilateral disease of the receptor apparatus of the snail - spiral organ.
If such a person has a tone perception of 1024 Hz up to 50 dB, then this tone with an audiometer is amplified up to 60 dB, and simultaneously served in both ears. In this case, the epipped intensity of sound for the patient ear will be equal to 10 dB, and for a healthy - 60 dB. Accordingly, there will be a difference in the volume of perception.
If then, gradually 5 -10 dB increase the outgoing intensity of the tones, then the difference in the volume between the two ears will quickly decrease due to the accelerated, compared to the norm, the increase in the volume in the patient's ear, and then this difference will not be at all. For example, the sound of 90 dB will be perceived equally both ears, i.e. The volume will occur. Such an alignment of the volume is because it is growing in a sick ear much faster than in a healthy ear. In this case, Fung is present, which indicates violations in the spiral snail body.
The second test of the outporn audiometry is determination of the differential threshold of the perception of the intensity of the sound.A definite-effectable threshold is carried out at frequencies of 125 - 4000 Hz with an intensity of 20 - 40 dB above the threshold of perception. The study begins with the supply of smooth tone, then it is replaced by oscillating, with a modulation frequency up to 2 Hz, with a gradual increase in amplitude until the studied has a sound oscillation. At the same time, a person is asked to raise the hand up, if the tone is smooth, and wave a brush in the beat if the sound starts to be interrupted.
Both tests are positive, or are present only with the defeat of the spiral, cortiyev organ and is absent for the disease of the auditory nerve.
In children with hearing loss using hearing aid With a large intensity of amplification, with a small discomfort threshold often arise unpleasant sensations with a slight increase in volume, which should be taken into account in the auditory work.
Speech audiometry.
Speech audiometry, or determining the intelligibility of speech sounds is used both to evaluate hearing disorders and to solve the question of prosthetics, since it is not always an increase in sound leading to an increase in hearing.
The speech is applied either from a tape recorder or live voice or perceived either through headphones, or in a free speech field. The advantage of filing text from a tape recorder is to use a standard entry in the form of verbal text out of 30 words, or 10 digits, which are supplied with a uniform intensity corresponding to the threshold of the perception of tons 1000 - 2000 Hz. To determine the threshold of the speech of the specified intensity of 30 words, calculate the percentage of repeated words.
The positive parties to speech audiometry include the creation of the maximum sound intensity and the ability to mask the non-studying ear, if the difference between the thresholds is more than 30 dB.
Technique of speech audiometry. Before studying, it is necessary to explain that the examination will hear the words in the headphone that it is necessary to listen to the most quiet sounds and clearly repeat the heard word out loud. The study begins with the intensity of the sound, which corresponds to the threshold of perception of the tone of 1000 Hz in this examined. Gradually add the intensity of the sound of 5 dB and determine the level of the intensity of the sound, on which the surveyed repeats half the words. On the audiogram, it is noted as a 50% threshold of words.
To determine 100% of the speech intelligibility threshold, the measurement is carried out at the intensity of the sound, exceeding the threshold of 50% of the intelligibility of 30 dB. If the examiner repeats all words, then a threshold of 100% of speech intelligibility is noted on the audiogram.
Analysis of the speech audiogram. On the Speech Audiogram Blanc, a speech intelligibility indicator in% is postponed along the ordinate axis, and on the abscissa axis, the intensity of speech in dB. In normally hearing threshold 50% of the intelligibility of the speech is achieved at 20 dB, and the threshold 100% of speech intelligibility at the intensity of 50 dB above the threshold of audibility of Tone 1000 Hz.
If the surveyed preserves such relations in the perception of the first and second tests and, at the same time, it works well a very long speech, then the function of the intelligibility of speech, despite the reduced rumor stored.
If the threshold of 100% of the speech intelligibility is achieved at a level exceeding the threshold of 50% of speech intelligibility by 40 dB and more, it is possible to conclude a slow-down increase in speech intelligibility.
Under the defeat of the sound handling, the increase in speech integrity curve repeats in the form of the curve normally hearing, but it is right away, towards large intensities. When impaired the function of sound perception, the speech intelligibility curve does not reach the level of 100% of the intelligibility and abruptly deviates to the right. With an increase in the intensity of the transmitted speech, the intelligibility may even decrease. Fig.57. Removability curves with speech audiometry.
The lack of complete intelligibility of speech with a satisfactory tonal hearing is observed when the conduction, and the central sections of the hearing system are often observed in the elderly. At the same time, the increase in the intensity of the sound causes a decrease in the intelligence of speech, in this case the auditory does not give necessary effect. Such disorders are associated with the pathology of the vascular system, when the function of brain nerve cells is disturbed.
Research of perception W. lawsuitused in Weber's experience for a hearing comparison between the left and right ear, since the lateralization of ultrasound is characterized by a large constancy and severity compared to low challenches. The low-frequency chain is perceived by examined both through the bone and through the air, which allows you to hear it through the air during the study through the bone, which is disturbed by the purity of Weber's experience. When studying Weber's experience with ultrasound, the ability to override sound through the air disappears. The presence of bone hearing sensitivity to ultrasound in the event of a nerve damage or cortiene organ is a favorable prognostic sign. At the deaf, as a rule, there is no perception of the sound of the camera at Weber's experience.
Implantation of electrodes in the inner ear.
The microphone, fixed behind the outer ear, catches the sounds and transmits them to the speech processor, located there. In the processor, the sounds obtained are encoded and transformed into electrical impulses. Next, they are across the transmitter, fixed on the skin enter the receiver located in temporal bone. From there, they go to the snail along the electrode and affect the spiral gangulia of the auditory nerve. Thus, the patient is able to perceive sounds.
The main task of the study of the hearing is to determine the hearing acuteness, i.e. the sensitivity of the ear to the sounds of different frequency. Since the sensitivity of the ear is determined by the hearing threshold for this frequency, the almost study of the hearing is mainly in determining the thresholds of perception for the sounds of different frequency.
3.1. Hearing a rumor speech
The simplest and most affordable method is a speech hearing study. The advantages of this method consist in the absence of the need for special devices and equipment, as well as in its compliance, the main role of the auditory function in humans is to serve as a means of speech communication.
When studying the hearing, a speech is applied whisper and loud speech. Of course, both of these concepts do not include accurate dosage The strengths and heights of the sound, but some indicators defining the dynamic (power) and frequency response of a whisper and speech speech, are still available.
In order to give a whisper speech more or less constant volume, recommended to pronounce words, using air remaining in the lungs after a calm exhalation. Virtually under normal conditions of research, the hearing is considered normal when perceiving a whisper speech at a distance of 6-7 m. The perception of the whisper at a distance of less than 1 m characterizes a very significant decrease in hearing. The complete absence of perception of a whisper speech indicates a sharp hearing loss that makes it difficult to communicate.
As it was above, the sounds of speech are characterized by formants of different heights, i.e. can be more or less "high" and "low".
Selecting words consisting of some of the high or low sounds, you can partly differentiate the lesions of the sound and sound visible apparatuses. To defeat the sound system, it is considered characteristic deterioration of low sounds perception, loss or deterioration of high sounds indicates the defeat of the sound-by-examination.
To study hearing a whisper speech, it is recommended to use two groups of words: the first group has a low frequency response and is heard at normal hearing on average at a distance of 5 m; The second - has a high frequency response and is heard on average at a distance of 20 m. The first group includes words that include vowels in, o, from consonants - m, n, r, in, for example: Crow, courtyard, sea, number , Murom and. t. p.; The second group includes words that include from agrees hissing and whistling sounds, and from vowels - a, and, uh: hour, soup, cup, chirik, hare, wool, etc.
In the absence of a sharp decrease in the perception of a whisper speech, go to the study of hearing with a speech. Initially, we use the speech of the average, or so-called spoken, volume, which is heard at a distance of about 10 times greater than the whisper. To give such a speech, more or less permanent volume level recommends the same reception that is proposed for a whisper speech, i.e., use the backup air after a calm exhalation. In those cases when the speech of colloquial volume differs poorly or does not differ at all, the speech of the enhanced volume (cry) is applied.
River's hearing study is produced for each ear separately: the ear studied is drawn to the sound source, the opposite of the ear muffled with the finger (preferably moistened with water) or woven wet lump. When the ear muffled, the finger should not press the hearing aisle with force, as it causes noise in the ear and may cause pain. When studying the hearing of the conversational and speech speech, turning off the second ear is produced using an ear ratt. Studying the second ear finger in these cases does not reach the goal, since in the presence of a normal hearing or with a slight decrease in hearing, this ear will differ, despite the complete deafness of the studied ear.
The study of speech perception should be started at close range. If the examined correctly repeats all the words that prevent him, then the distance gradually increases until most of the words pronounced. The threshold of perception of speech is considered the greatest distance, on which 50% of the words are distinguished. If the length of the room in which the hearing study is carried out is insufficient, i.e. when all words are well differentized even at the maximum distance, it can be recommended that such a reception: the investigator becomes back to the study and pronounces words in the opposite direction; This approximately corresponds to the increase in distance have.
When studying hearing, the speech must be borne in mind that the perception of speech is a very complex process. The results of the study depend, of course, on the acuteness and volume of hearing, that is, on the ability to distinguish between the sounds of a certain height and force corresponding to the acoustic properties of speech. However, the results depend not only on the acuteness and volume of hearing, but also on the ability to distinguish between the hearing elements of speech, as the phones, words, their compounds in the proposals, which, in turn, is due to the fact that the audio speech was observed.
In this regard, exploring the hearing with speech, it is necessary to be considered not only with the phonetic composition, but also with the availability of applicable words and phrases for understanding. Without taking into account this last factor, you can come to an erroneous conclusion about the presence of certain ear defects where there are really no these defects, and there is only a mismatch of the speech development of the speech development used to study the hearing of the speech.
With all its practical significance, the study of the speech hearing cannot be taken as the only method of determining the functional ability of the auditory analyzer, since this method is not fully objective, both in the sense of dosage of sound force and regarding the evaluation of the results.
3.2. Study of hearing Tamertonami
A more accurate method is a study of hearing with the help of tubers. Tambletones make clean tones, and the height of the tone (oscillation frequency) for each chamberton is constant. In practice, tuners are usually used for tone with (up to) in different octaves, including tubes C, C, C, CV C2, C3, C4, C5. Hearing studies are usually produced three (C128, C512, C2048 or C4096) or even two (C128 and C2048) by chalktones (footnote: For greater clarity, the tones are denoted by the letter corresponding to the title of the tone published by this Charton, and the number indicating the number of oscillations (C256, C1024, etc.) per second).
Tambleton consists of legs and two branches (branches). To bring the camera to the sound of the Branches, hit any object. After the Camerton began to sound, should not be touched by his hand to his hand and can not be touched by the branches to the ear, hair, clothing studied, as it stops or shortens the sound of the camera.
With the help of a set of tapes, it is possible to study hearing both in terms of its volume and in relation to sharpness. When studying the volume of auditory perception, the presence or absence of perception of this tone is determined at least with the maximum sound of the soundtrack. In the elderly, as well as during diseases of the sound, the volume of hearing is reduced by the perception of high tones.
The study of the hearing acuity by the tunes is based on the fact that the Tambleton, being entered into oscillation, sounds for a certain time, and the sound power decreases accordingly to a decrease in the amplitude of the chamber oscillations and is gradually coming down.
Due to the fact that the duration of the sound of the charterone depends on the strength of the blow, with which the tape is given to the sound state, this force should always be maximum. Low tunes hit the branches about their elbow or knee, and high - about the edge of the wooden table, about any other wooden item.
research of the air conductivity of the trimmed of the sound of the camera is made to the outer auditory passage of the studied ear (Fig. 18) and determines the duration of the sound of the chamberon, that is, the period of time from the beginning of the sound until the sound of audio audibility disappears.
Fig. 18. Hearing a hearing Tampert (air)
Bone conductivity is investigated by pressing the leg of the sounding tape to the cottage process of the studied ear or to the theme (Fig. 19) and determining the time interval between the beginning of the sound and the cessation of audio audibility. For the study of the bone conductivity, only low chainsons are used (usually C128). High tunes for this purpose are unsuitable, since the oscillations of the high-chart bears are transmitted through the air much better than the oscillations of its legs through the bone, and therefore bone conductivity is masked in these cases of air.
Fig. 19. Hearing a hearing of Tambleton (bone holding)
The study of air and bone conductivity has a significant diagnostic valueSince it makes it possible to determine the nature of hearing damage: whether in this case only the function of the sound system is affected or there is a lesion of a sound-by-obstinate apparatus. For this purpose, three main experiences are produced: 1) determination of the duration of the perception of the sound of the camera at bone conducting; 2) a comparison of the duration of the perception of the sound of the camera with air and bone securities; 3) the so-called lateralization experience (from lat. Laterum - side, side).
1. Referring to the camera to the state of the sound, put it with the leg to the theme and determine the duration of the perception of its sound. The shortening of the bone conduction compared to the norm indicates the defeat of the sound of the vehicle. With a violation of the sound-conducting function, the bone conductivity elongation is observed.
2. Compare the duration of the sound of the chamberon when it is perceived through the outer hearing pass (air conduction) and through a chipped process (bone conductivity). With a normal hearing, as well as the damage to the sound-by-penetrating apparatus, the sound through the air is perceived longer than through the bone, and when the sound conductive apparatus is violated, the bone conductivity is equal with air and even exceeds it.
3. The leg of the sounding chamber is put on the middle of the pattern. If the studied has one-sided hearing damage or bilateral defeat, but with a predominant hearing impairment for one ear, then the experience of the so-called lateralization of sound is noted. It lies in the fact that, depending on the nature of the defeat, the sound will be transmitted in one direction or the other. With the defeat of the sound-by-obstinate apparatus, the sound will be perceived healthy (or better hearing) ear, and when the sound-conducting device is impaired, the sound will be felt in the patient (or worse hearing) ear.
With a long-term continuous sound of the tuning, the phenomenon of adaptation of the auditory analyzer occurs, i.e. the decrease in its sensitivity, which leads to shortening the time of the perception of the sound of the chamberon. In order to exclude adaptation, it is necessary during the study of both air and bone conduction from time to time (every 2-3 seconds) to be removed by 1-2 seconds of the tape from the studied ear or from the temperature and then to bring it back.
By comparing time during which the sound of the chamberon is perceived by the studied ear, with the duration of the sound of the same equipment for the normal hearing ear, and the hearing acuity is determined to the sound published by the Chainton. The duration of sound during normal hearing, or, as they say, the sound rate must be determined for each tape in advance, and moreover, separately for air and for bone conductivity. The numbers characterizing the sound rate of each tape should be applied to each set. They are the so-called Tameton Passport.
Table 3. Approximate Table of Lean Research Results Tammount Ear Tamper Left Ear
20 with C128 (40C) 25 s
20 with C256 (30C) 20 s
15 with C512 (70C) 20 s
5 with C1024 (50c) 10 s
0 with C2048 (30C) 5 s
0 with C4096 (20c)
Bone hold 0 s
3 with C129 (25C) 4 s
The numbers standing in brackets near the names of the tapes in the middle column of the table, indicate the duration of the sound of the tubes normally (the passport details of the Tambleton). In the right and left columns, the duration (in seconds) of the soundtrack of tubes, obtained in the study of this subject, is affixed. Comparing the duration of the perception of the sound of the tubes subjects with the duration of their sound for normal hearing, it is possible to obtain an idea of \u200b\u200bthe degree of esteem's preservation on certain frequencies.
A significant drawback of tubes is that the sounds published by them do not have sufficient intensity to measure the thresholds with very large hearing loss. Low tubes give the volume level over the threshold of only 25-30 dB, and medium and high - 80-90 dB. Therefore, in the study of chamberlons of persons with a large loss of hearing, not true, and false hearing defects, i.e., the resulting hearing spaces may not correspond to reality.
3.3. Audiometer hearing study
The more advanced method is the study of hearing with the help of a modern apparatus - an audiometer (Fig. 20).
Fig. 20. Study of hearing with an audiometer
The audiometer is an electrical voltage variable generator, which are turned into sound oscillations using the phone. For the study of hearing sensitivity in air and bone conductors, two different phones are used, which are respectively called "air" and "bone". The intensity of sound oscillations can vary in very large limits: from the most insignificant, underlying the threshold of the auditory perception, up to 120-125 dB (for the sounds of the average frequency). The height of the audiometer published audiometer can also cover a large range - from 50 to 12,000-15,000 Hz.
Meaning the audiometer is extremely simple. By changing the frequency (height) of the sound by pressing the corresponding buttons, and the intensity of the sound - by rotating the special handle, set the minimum intensity at which the sound of this height becomes barely audible (threshold intensity).
Changing the height of the sound is achieved in some audiometers by smoothly rotating a special disk, which makes it possible to obtain any frequency within the frequencies of this type of audiometer. Most of the audiometers emit a limited amount (7-8) of certain frequencies, chainning (64,128.256, 512 Hz, etc.) or decimal (100, 250, 500, 1000, 2000 Hz, etc.).
The audiometer scale is separated in decibels usually in relation to normal hearing. Thus, by identifying the threshold intensity of the threshold intensity on this scale, we thus define hearing loss in decibels for the sound of this frequency in relation to normal hearing.
On the presence of hearingness, the subject signals a raised hand, which he must keep raised throughout the whole time, while he hears the sound. The signal of hearing is the lowering of the hand.
amp on the audiometer panel. The test holds the button down all the time until the sound hears - therefore, the warning light is on all this time. With the disappearance of audio sound, the subject releases the button - the light bulb goes out.
When studying the hearing, the audiometer should be placed the subject so that it does not see the front of the audiometer and could not follow the actions of the exploring, switching handle and the audiometer buttons.
The result of a hearing study by an audiometer is usually represented as an audiogram (Fig. 21). On a special audiometric grid, on which sound frequencies (64, 128, 256, etc.) are shown horizontally, and vertically - the volume levels of the corresponding sounds on the threshold of hearingness (or that the same thing, hearing loss) in decibels, Applied in the form of points of testimony of an audiometer for each ear separately. The curve connecting these points is called an audiogram. By comparing the position of this curve with a line corresponding to normal hearing (usually this line is represented as a direct passing through the zero level), you can get a visual representation of the state of the hearing function.
Fig. 21. Sample audiogram
The results of the study of both ears enter the same form. To distinguish audiograms for each ear, it is recommended to apply the results of the study of the right and left ears of different conventional signs to an audiometric grid. For example, for the right ear - circles, and for the left - crosses (as shown in Fig. 21), or draw the curves with pencils different color (For example, for the right ear - a red pencil, for the left - blue). Curves depicting the result of a bone conductivity study are applied by a dotted line. All conditional designations are negotiated on the fields of an audiometric form.
The audiogram not only gives an idea of \u200b\u200bthe degree of violation of the hearing function, but also allows to a certain extent to determine the nature of this violation. We give for example two typical audiograms. In fig. 22 shows an audiogram characteristic of sounding impairment, as evidenced by a relatively small degree of hearing loss, the ascending type of air conduction curve (i.e., the best perception of high tones compared to low) and normal bone conductivity. In fig. 23 shows an audiogram, typical of the lesion of a sound visible apparatus: a sharp degree of hearing impairment, a downward audiometric curve, a significant decrease in bone conductivity, breaking the curve, i.e. the absence of high tones perception (4000-8000 Hz).
125 250 500 1000 2000 4000 8000 Hz
Fig. 22. AUDIOGRAPH DISPERTANCE
Fig. 23. Audiogram with violation of sound perception (conditional designations are the same as in Fig. 22)
Recently, the so-called speech audiometry is widely used in the practice of studying hearing. While when ordinary, or tonal, audiometry, hearing sensitivity in relation to pure tones is investigated, at speech audiometry, the threshold of discouraging speech is determined. In this case, either a natural speech (through the microphone) is submitted to the audiometer (through the microphone), or speech pre-recorded on the film using a tape recorder. The threshold of distinction, or the minimum speech intensity, in which the studied distinguishes the majority of words that prevent him is determined in the same way as with a tonal audiometry, and is measured in decibels (Fig. 24).
10 20 30 40 50 60 70 80 90 100 110 120DB
Fig. 24. Speech audiograms.
Speech integrity curves: I - normally; II - when impaired sounding;
III - when impaired sound perception
Compared to other methods, research with an audiometer represents a number of advantages. Such advantages include the following.
1. Significantly greater measurement accuracy. The inaccuracy of the results of measuring hearing acuity by voice and speech has already been mentioned, as applies to the study by the tortons, then this method cannot claim accuracy, since the duration of the sound of the chamberton depends on a number of reasons, in particular from the initial amplitude, i.e. from force Strike.
2. Significantly greater opportunities regarding the range of sound frequencies. The highest challenge has a frequency of oscillations of 4096 Hz, the audiometer can give, as indicated, up to 12,000-15,000 Hz; In addition, an audiometer with a smooth change in frequency can be made of sounds that are not only corresponding to the height of the tortones, but also any intermediate frequencies.
3. Significantly greater opportunities regarding the volume of the sounds of the sounds. Challenges and voice of a person have the maximum volume measured in 90 dB, with the help of an audiometer, you can get the volume up to 125 dB, which makes it possible to determine in some cases the thresholds of an unpleasant feeling.
4. Significantly large studies of the study, especially in relation to the number of time spent on the study.
5. Ability to evaluate hearing acuity in conventional and easily compared units (decibels).
6. The ability to explore bone conductivity for high sounds, which is excluded in the study of hearing by the camera.
Like other methods based on the testimony of the subject, study using an audiometer is not free from some inaccuracies associated with the subjectivity of these testimony. However, by repeated audiometric studies, it is possible to usually establish a significant consistency of the research results and, thus, this results are sufficient persuasive.
3.4. Hearing research in children
The study of hearing in children should be presented to collect brief anamnestic information: the course of the early physical development of the child, speech development, time and cause of hearing loss, the nature of speech loss (simultaneously with the deafness or after some time, immediately or gradually), the conditions of child education.
In different periods of the child's life, the occurrence of hearing loss and deafness is associated with certain typical reasons, allowing to highlight risk groups. For example: the reasons affecting the hearing function of the fetus during pregnancy (congenital hearing loss and deafness) is toxicosis, the threat of miscarriage and premature births, the rhesus conflict of mother and fetus, nephropathy, uterus tumors, the disease of the mother during pregnancy, first of all such Like rubella, flu, treatment with ototoxic drugs. Often, deafness occurs in pathological types - premature, rapid, protracted with bleaching, with a cesarean section, partial placental detachment, etc. For deafness coming in the early neonatal period, hyperbilirubinemia, associated with hemolytic diseases of newborns, prematurity, congenital vices development, etc.
In breast and early childhood, risk factors are transferred sepsis, feverish state after childbirth, viral infections (rubella, chickenpox, Cort, vapotitis, influenza), meningo-encephalitis, complications after vaccinations, inflammatory diseases of the ear, cranial and brain injuries, treatment with withdoxic drugs, etc. Affects congenital deafness and heredity.
Of great importance for the initial judgment about the state of hearing in a child with suspicion of hereditary hearing loss has a maternal history:
· In the poll of the parents of a child under the age of 4 months, it turns out: whether the sleeping unexpected loud sounds awaken, whether he shudders or cry; For the same age, the so-called reflex moro is characteristic. It is manifested by breeding and handling of hands (crush reflex) and foot stretching with strong sound irritation;
· For the estimated detection of hearing disorders, a congenital sucking reflex is used, which occurs in a certain rhythm (as well as swallowing). The change in this rhythm in sound exposure is usually captured by the mother and testifies to the presence of hearing. Of course, all these indicative reflexes are rather determined by their parents. However, these reflexes are characterized by a rapid fading, which means that with frequent repetition, the reflex can stop playing. At the age of 4 to 7 months, the child usually makes attempts to rotate to the sound source, i.e. it already determines its localization. In 7 months, it differentiates certain sounds, even reacts, if not sees the source. By 12 months, the child begins attempts by speech answers ("Busting").
To study the hearing of children aged from 4-5 years, the same methods are used as for adults. Starting from 4-5 years of age, the child understands well what they want from him, and it usually gives reliable answers. However, in this case, it is necessary to take into account some features of children's age. So, although the study of hearing with a whisper and colloquial speech is very simple, it is necessary to comply with the exact rules for its holding to obtain a correct judgment about the state of the auditory function of the child. The knowledge of this method is especially important, as it can be carried out by a doctor on its own, and the identification of any loss of hearing is the basis for directions to a specialist. In addition, a number of peculiarities of a psychological nature that take place in the study of this technique in childhood should be taken into account.
First of all, it is very important that confidence arises between the doctor and the child, since otherwise the baby just will not answer the questions. It is better to give dialogue the character of the game with the involvement of any of the parents into it. At the beginning, contacting the child to some extent to interest it, for example, in such a question: "I wonder if you will hear what I will say a very quiet voice?" Usually, children sincerely rejoice, if the word can repeat, and willingly be involved in the process of research. And, on the contrary, they are upset or closed in themselves, if they do not hear the words from the first time.
Children need to start a study from close range, only then increases it. The second ear is usually drowning to eliminate the listeind. Adults are simple: a special ratchet is applied. In children, its use usually causes a fright, so the drill is caused by a slight pressure on the goat with his stroke, which is better to make parents.
The study of the hearing should be carried out in conditions of complete silence, in an isolated area of \u200b\u200bindoors isolated. To eliminate the possibility of the vibrational perception of sounds, under the feet under the test it is necessary to lay a soft rug, as well as to trace the mirror or any other reflective surface before the eyes of the child, which would allow him to observe the actions of the hearing exploration.
To exclude or at least reduce the child's reaction and to quickly establish contact with it, the hearing study is recommended in the presence of parents or teacher. With a sharply negative attitude of the child, the study may be useful in the presence of a hearing study in other children, after which negativism is usually removed.
Before the study, it is necessary to explain to the child how it should respond to the audible sound (to turn around, specify the sound source, play the heard sound or word, raise the hand, press the audiometer signal button, etc.).
To eliminate the tactile feeling from the air jet and the possibility of reading the lips when studying the hearing voice and speech, you need to use the screen closing the face of the explore. Such a screen can serve a piece of cardboard or sheet of paper.
The study of hearing in children is conjugate with great difficulties. They are due to the fact that the kids cannot focus on one activity and are easily distracted. Therefore, the study of hearing in young children needs to be carried out in an entertaining form, for example in the form of the game.
When studying hearing in children of predos-school and junior preschool age (2-4 years), you can already use speech, as well as various sounding toys.
The study of the auditory perception of votes is connected to the definition of the ability in children distinguish between the vowels, which are first taken in a certain sequence, taking into account their hearing, for example, and, o, e, and, y, and then, to avoid guessing, are offered in any order . For the same purpose, dyphthongs of AU, UA, etc. can be used. It is also examined by the distinguisure of consonants in words that differ from each other with one consonant sound or in syllables.
In the study of the auditory perception of such elements of speech, as words and phrases, a material that meets the level of speech development of children is used. The most elementary material is such, for example, words and phrases as the name of the child, for example: Vanya, Mom, Dad, Grandfather, Grandma, Drum, Dog, Cat, House, Vova fell, etc.
The distinction of the elements of speech is best to carry out with the help of pictures: when dealing with the exploring of a particular word, the child should show the appropriate picture. When studying the hearing of speech in children, still beginners to speak, you can use sound resistance: "AM-AM" or "AV-AB" (dog), "meow" (cat), "MU" (cow), "TPRU" ( Horse), "Tu-TU" or "BB" (car), etc.
To study the distinction of a whispering speech in children of senior pre-school and junior school age, the following approximate table of words can be applied (Table 4).
Table 4 Word Tables for Study Speech In Children
Words with low frequency characteristic of the word with high frequency response
Vova Sasha
Ship window
Sea matches
Fish Chizhik
Wolf Shashka
City bunny
Raven Clash
Soap bird
Lesson brush
Bull Chaika
For the study of phonderatic hearing, i.e. the ability to distinguish from each other separately among themselves in acoustic relationship sound sounds (phonemes), it is necessary, where it is possible to use specially selected, affordable pairs of words that would differ from each other phonetically Only sounds whose differentiation is investigated. As such steam can be used, for example, such as heat - a bowl, a cup - a checker, a dot - daughter, kidney - barrel, goat - spit, etc.
This kind of pair of words can be successfully applied to the study of the diffraction of vowels. Here are some examples: stick - shelf, house - smoke, table - chair, teddy bear - mouse, mouse - fly, etc.
If it is impossible to choose the appropriate pairs of words, the study of distinguishing conscious sounds can be carried out on the material of the syllables of the type AMA, Ana, Ala, Ave, etc.
Table 5 Exemplary Table Results Research Research on Voice and Elements Rechintensive Voice Quest Distribution of Words and Frase Distance
Does not distinguish not distinguish
Distribution of vowels y / r (a, y) does not distinguish
Distribution of consonants U / P (R, W) does not distinguish
The distinction of words and phrases does not distinguish not distinguish
Distinction of vowels y / p (a, y, o, and) u / p (a, y)
Distinguishing words and phrases U / P (dad, does not distinguish
Vova, grandmother)
Conducting chain and audiometric studies in children up to 4-5 years old is practically impossible and manifest only as a rare exception. In many cases, the senior preschoolers, in many cases, it is possible to conduct a study of hearing by tunes or an audiometer, however, such a study requires some preparatory techniques.
Before studying, you need to explain to the child what is required of it. Initially, an approximate study is produced, i.e., find out if the child understood the task. To do this, drive a tank's ear, sounding with maximum volume, or a loud audiometer telephone headphone and, having received a signal (verbal or raising a hand) about the availability of sound, immediately imperceptibly for the test, the tape tap touching the finger to its bears or turn off the audiometer sound. If the test signal signals the termination of hearing, it means that he correctly understood the task and correctly reacts to the presence of a sound stimulus and its absence.
Sometimes it is necessary to spend a lot of time so that the child began to respond to the sound of the chamberton or an audiometer, and in some cases such a reaction is produced only during repeated studies.
Special difficulties arise in the study of auditory perception in children who do not speak speech and not detecting explicit residues of hearing. The use of an audiometer and chalktones often does not lead to a goal, since children may not understand the tasks set before them. Therefore, the primary study of such children is better to spend with the help of sounding toys and voices. The behavior of a child manipulating with sounding toys, as well as the absence or presence of a reaction to a sudden toy-published sound help to determine if a child has a rumor.
As sound items can be used musical instruments: drum, tambourine, triangle, harmonica, metallophone, twin, whistle, bell, as well as animal pictures sounding toys, emitting the sounds of different tonality. Initially, the child makes it possible to get acquainted with these objects and their sound, hold in your hands, and then lead one of the toys of a similar set so that the child does not see this, and ask him to show what item sounded.
When using sounding toys, you can recommend such a reception. The child gives two similar toys: two twins, two harmonica, two roosters, two cows, etc. One of these toys sounds, the other is spoiled. In most cases, it is possible to notice a distinct difference in the behavior of a deaf child and a child having more or less significant residues of hearing. The hearing child usually easily finds that one of the toys does not sound, and begins to manipulate only sounding. Deaf or pays the same attention to both toys, or both leavesless.
If the child does not detect the reaction even on very loud sounds (shouting or loud toys) and at the same time clearly reacts to vibrating stimuli, for example, when you tapping the foot on the floor or onto the door knock, you can with a significant share of the probability of incorporation on availability Deafness.
Lack of reaction to such stimuli, like a knock door, a blow on the table, a top of the foot on the floor, may indicate not only the deafness, but also about the violation of other types of sensitivity or a sharp decrease in overall reactivity. In these cases, the child must be examined by a psychoneurologist.
In the study of hearing, children often use slamming in your hands behind the baby. This reception is not sufficiently reliable, since the response in the form of turning of the head may occur in a deaf child as a result of exposure to the skin of air jolts.
In general, it should be emphasized that a single primary study of hearing in children rarely gives quite reliable results. Repeated research is very often required, and sometimes the final conclusion about the degree of hearing impairment in a child can be given only after a long (semi-annual) observation in the process of upbringing and learning in a special institution for children with hearing impairment.
In the study of the perception of the deaf and weast-hearing children of the speech elements, the corresponding speech material (phonemes and words) is proposed at the beginning to distinguish between the chairs at the same time, to read the lips and using tactile-vibration perception. The explorer utters loudly to the background or the word, and the child listens, looks at the face of the explorer and keeps one hand on the chest explored, the other - on his chest. Only after the child will begin to confidently differentiate the elements of speech with such a complex perception, it is possible to proceed to the study of their perceptions only on rumor.
Studying hearing with speech in children with hearing impairments and speech cannot, as a rule, to identify the true state of hearing sensitivity. This category of children differing on the hearing of the elements of speech, being in direct dependence on the degree of hearing impairment, is at the same time due to speech development. A child with a reduced hearing who owns a verbal speech, differentiates all or almost all acoustic differences available to it, which is available to it, since these differences have a signal (senseless) value for it. Another thing is a child who does not speak speech or owning it only in its infancy. Even in cases where a particular element of speech is in its acoustic characteristic available to its auditory perception, it can not be recognized as such a child due to the absence or insufficient strengthening of its signal value. Thus, the study of hearing with speech in children with a violation of speech development gives only a general idea of \u200b\u200bhow the child is currently implementing its auditory opportunities to distinguish certain elements of speech.
An audiometry is used to accurately determine the hearing sensitivity and the volume of auditory perception. However, the use of conventional acudometrics in children with hearing impairment and speech meets significant difficulties that are due to two main reasons: firstly, such children do not always understand the speech instructions, in which the task and methods of responding to sound signals are explained, and The second, such children usually lack listening to the sounds of low intensity. In these cases, the child reacts to the sound not at minimal (threshold) its strength, and at some, sometimes quite significant exceeding the threshold intensity.
Thus, the study of the auditory function of children even at the age of 4-5 years is significant difficulties compared with the study of adults, although they are based on the answers of the surveyed. All these methods using speech, tuning, or audiometers are called psychophysical.
However, unfortunately, these psychophysical methods can be used in children not earlier than 4-5 years of life, for before this age, the child is usually unable to give the correct answer. Meanwhile, it is in this and even earlier age that there is an urgent need to identify hearing loss, since it is most closely associated with the development of the speech function and the intellect of the child. In addition, 80% of hearing disorders arise in children on the 1st-2 year year of life. The main problem here is that the late diagnosis of hearing loss leads to late treatment of treatment, and therefore, to late rehabilitation, delay in the formation of speech in a child. The modern concept of survival of survival and audience is also based on an earlier beginning of learning.
The age of 1-1.5 years of the child is optimal for the audience. If this time is overlooked that, unfortunately, each third patient occurs, it is already much more difficult to teach him any more difficult - it means that the child has more chances to become deaf-and-and-the-day.
In the whole multifaceted problem, one of the most important issues is the early diagnosis of hearing loss, which is in the field of pediatrician and otolaryngologist. Until recently, this task remained almost intractable. As already noted, the main difficulty was to carry out an objective study based on the child's answers, and some other criteria that are independent of his consciousness.
When studying hearing in children of chest and early age Methods are based on registration of a response (motor reaction, change in electric potential, etc.) on sound irritation, independent of the child's consciousness.
Current methods of hearing research can be divided into three large groups: 1) the method of unconditional reactions; 2) the method of conditionally reflex links; 3) Objective electrophysiological methods.
Methods of unconditional reflexes. This group of methods is quite simple, but very inaccurate. The decision of the hearing here is based on the occurrence of unconditional reflexes in response to sound irritation. According to these, the most diverse reactions (pulse rapidity, pulse frequency, respiratory movements, motor and vegetative answers) indirectly can be judged, hears the child or not. A number of recent research shows that even the fruit in the mother's womb reacts around the 20th week to sounds, changing the rhythm of heart abbreviations. The data involving the embryo is heard the frequency of the speech zone. On this basis, there is a conclusion about the possible reaction of the fetus for the speech of the mother and the beginning of the development of the psycho-emotional state that has not yet born child. The main contingent of the application of the method of unconditional reactions is newborn and breast-age children. Hearing child must respond to the sound immediately after birth, already in the first minutes of life. These studies use different sound sources: sounding, pre-calibrated toys, ratchets, musical instruments, as well as simple appliances, such as sound reactuetters, sometimes narrow broadband noise. The intensity of sound is different.
The general principle is that, the older the child, the smaller the intensity of the sound is necessary to identify its reaction. So, in 3 months, it is caused by the intensity of 75 dB, in 6 months - 60 dB, at 9 months to manifest the reaction at a hearing child, 40-45 dB is already enough.
Very important both proper conduct and the interpretation of the results of the methodology: the study must be carried out in 1-2 hours before feeding, since later the reaction to the sounds decreases. The motor response can be false, i.e. not on sounds, but simply on the approach of adult or the movement of his hands, therefore pauses should be taken in contact with the child. To eliminate false-positive reactions, a two-three-time identical answer can be considered reliable. Many mistakes in determining the unconditional reaction eliminates the use of a "baby bed" specially equipped to study. The most common and learned types of unconditional reflexes are: blinking in response to sounds; expansion of the pupil; motor estate reflexes; Violation of the rhythm of braking of a sucking reflex.
Some responses are possible to objectively register, for example, a change in the lumen of vessels (plethismography), heart rhythms (ECG), etc.
The positive parties to this group of methods include simplicity, availability in any conditions, which allows them to be widely used in the medical practice of the neonatologist and pediatrician.
The disadvantages of unconditional reflexes are that a rather high intensity of sound and accurate compliance with the rules for the study to eliminate false-positive answers is mainly in one-sided hearing loss. In addition, it is possible to find out if the child hears, without the characteristic of the degree of hearing loss and its signs, although it is extremely important. Using this technique of unconditional reflexes, you can try to determine the ability to localize the sound source, which normally develops in children from 3-4 months after birth.
Thus, it can be noted that a group of unconditional reflexes is widely used in practical work For the purpose of screening diagnostics, especially in risk groups. With the opportunity, all newborn and breast children still in the maternity hospital should conduct similar studies and consultations, but they are mandatory in so-called risk groups on hearing loss and deafness.
Methods based on the use of conditionally reflex reactions. For these studies, it is preliminarily necessary to develop an approximate reaction not only to the sound, but also to another stimulus, supporting sound. So, if you combine feeding with a strong sound (for example, a call), then after 10-12 days, the sucking reflex in the child will occur only in response to the sound.
There are numerous techniques based on such regularity. Only the nature of reinforcement of reflex changes. Sometimes pain irritants are used as it, for example, the sound is combined with the shock or direction of a strong air jet in the face. Such reinforcing sound stimuli cause a defensive reaction (rather stable) and are mainly used to identify aggravation in adults, but cannot be applicable to children from humane considerations.
In studies of children, such modifications of conditionally reflex techniques are used, which are not based on a defensive reaction, but on the contrary, on the positive emotions and the natural interest of the child. Sometimes food (candy, nuts) gives food (candies, nuts), but this is not harmless, especially with repeated repeat, when you need to develop reflexes for different frequencies. Therefore, this option is more applied to the training of animals in the circus.
Now the game audiometry is often used in clinics (Fig. 25) in which the child's natural curiosity is used as a reinforcement. In these cases, the sound irritation is combined with the display of pictures, slides, video films moving toys (for example, the railway), etc. The technique scheme is as follows: the child is placed in a sound-effective and isolated chamber. The earphone joined the ear, connected to any sound source (audiometer). The doctor and recording equipment are outside the camera. At the beginning of the study, high intensity sounds are served in the ear, which the child knowsly hear. The baby's hand is put on the button that a mom or assistant presses when the sound signal is applied. After a few exercises, the child usually absorbs that the combination of sound with pressing the button leads to either to change the pictures, or to the continuation of the video film demonstration, in other words, to the continuation of the game. Therefore, it already presses the button independently when the sound appears. Gradually, the intensity of the sounds of the sounds is reduced.
Thus, conditionally reflex reactions make it possible to identify: 1) one-sided hearing loss; 2) determine the thresholds of perception; 3) give the frequency response of the discount disorders.
The study of hearing with these methods requires a certain level of intelligence and understanding from the child. Much depends on the ability to establish contact with parents, qualifications and a skilled approach to the child from the doctor. However, all efforts are justified by the fact that from the age of three, in many cases, it is possible to conduct a study of hearing and obtain a full-fledged characteristic of the state of the auditory function of the child.
Objective electrophysiological methods. Measurement of acoustic impedance, i.e. resistance, which has a sound engine wave.
Under normal conditions, this resistance is minimal: at frequencies 800-1000 Hz almost all sound energy reaches without resistance of the inner ear, and the acoustic impedance is zero.
In pathology associated with the deterioration of the functions of the eardrum, auditory bones, windows of the maze, part of the sound energy is reflected. It is the criterion for changing the size of the acoustic impedance.
This study is as follows. In the outer hearing pass, the impedance meter sensor is hermetically introduced; The sound of constant frequency and intensity called "probing" is supplied to the closed cavity. The data obtained during acoustic impedancemetry is recorded in the form of various curves on tympolism (Fig. 25).
Learn three tests:
· Tympanometry (gives an idea of \u200b\u200bthe mobility of the eardrum and pressure in the medium ear cavities);
· Static complix (makes it possible to differentiate the chain of the circuit of the auditory bones);
· The threshold of acoustic reflex (based on the contraction of the muscles of the middle ear, allows you to differentiate the damage to the sound and sound-by-handing machine).
Features that should be considered when conducting acoustic impedinsmetry in childhood. In the first month of life, the study does not pose a lot of difficulties, as it can be carried out during a sufficiently deep sleep, coming after another feeding. The main feature at this age is associated with frequent absence of acoustic reflex.
Tympanometric curves are recorded quite clearly, although there is a large scatter of the amplitude of the tympolism, which sometimes has a double configuration. Acoustic reflex can be determined approximately starting from 1.5-3 months. However, it should be borne in mind that even in a state of deep sleep in a child, frequent swallowing movements occur, so the recording may be distorted by artifacts. For sufficient reliability, research must be multiple.
It should also be considered the possibility of errors in acoustic impedancery due to the adequacy of the walls of the external auditory passage and changes in the size of the auditory pipe during a cry or crying. Of course, the anesthesia can be used in these cases, but this leads to an increase in the thresholds of acoustic reflex. It can be considered that tympumps become reliable since age in 7 months and give a reliable idea of \u200b\u200bthe function of the hearing pipe.
The method of objective determination of auditory caused potentials using computer audiometry (Fig. 26). Already at the beginning of the century, with the discovery of electroencephalography, it was clear that in response to sound irritation (stimulation) in various departments of the sound analyzer (snail, spiral ganglia, cores of the trunk and cerebral core) arise electrical responses (caused by auditory potentials). However, they were not registered due to a very small amplitude of the response wave, which was less than the amplitude of the constant electrical activity of the brain (A-, y-waves). Only with the introduction into the medical practice of electronic computing equipment was possible to accumulate in memory of the car separate minor responses to a series of sound incentives, and then summarize them - the summary potential
Fig. 26. Study of hearing with an objective computer audiometry for auditory caused potentials
A similar principle is used when conducting an objective computer audiometry. Multiple sound stimuli in the form of clicks are fed to the ear, the machine remembers and summarizes the answers (unless, of course, the child hears), and then represents the general result in the form of a certain curve.
Objective computer audiometry allows you to conduct a hearing study at any age of a child, even by the fetus, starting from his 20th week.
In order to obtain an idea of \u200b\u200bthe place of damage to the sound analyzer, on which the reduction of hearing (topical diagnostics) depends, the following methods apply.
Electro-churchography is used to measure the electrical activity of the snail and spiral node. For this, the electrode with which the electrical responses is distinguished, installed in the region of the exterior auditory pass or on the eardrum. This procedure is pretty simple and safe, but the returned potentials are very weak, as the snail is quite far from the electrode. Therefore, in the necessary cases, the electrode is punctured by the eardrum and it is placed directly on the inner wall of the drum cavity near the snail, i.e. at the place of generation of potentials. In this case, it is much easier to measure them, but in children's practice such a transducer ecog has not received a large distribution. The presence of spontaneous perforation of the eardrum significantly facilitates the situation. Ecog - the method is quite accurate and gives an idea of \u200b\u200bhearing thresholds, helps differential diagnosis Conductive and neurosensory touginess. Up to 7-8 years, it is carried out under anesthesia, at an older age - under local anesthesia. Ecog makes it possible to make an idea of \u200b\u200bthe state of the hairs apparatus of the snail and spiral node.
The definition of the short, medium of longolatent auditory caused potentials is carried out to study the state of a deeper underlying audio departments. The case is that the response at sound stimulation from each department comes in time slightly later, i.e. it has its latent period, more or less long. Naturally, the reaction from the cortex of large hemispheres occurs the latter, and thus longolaten potentials are precisely their characteristic. These potentials are reproduced in response to sound signals of sufficient duration and differ even by tonality. The latent period of short-prophent stem potentials continues from 1.5 to 50 mg / s, cortical - from 50 to 300 mg / s. Sound source - sound clocks or short tonal parcels that do not have tone coloring, which are served through headphones, bone vibrator. The active electrodes are installed on a chipidate process, attached to the urine or fix at any point of the skull. The study is carried out in a sound-insulated and electric-writing chamber in children up to 3 years in a state of their medication after the introduction of relatium (s) or a 2% solution of chloralhydrate rectally in a dose corresponding to the mass of the child's body. The study continues on average 30-60 min in the lying position.
As a result of the study, a curve, which has up to 7 positive and negative peaks is recorded. It is believed that each of them reflects the state of a certain audio analyzer department: I - auditory nerve; II-III - cochlear nuclei, trepacy-shaped body, upper olive; IV-V - lateral loops and upper bugs of quadruses; VI-VII - internal crankshaft (Fig. 27). There is a large variability of the responses of short-prophent auditory caused potentials (CSTVP) not only in the study of hearing in adults, but also in each age group. The same applies to longolatent auditory caused potentials (DSvP). In this case, many factors should be taken into account in order to make an accurate idea of \u200b\u200bthe state of the child's hearing function and localization of the place of defeat.
Fig. 27. Study of hearing with reverse acoustic emission
Literally recently, a new method begins to be implemented in the practice of hearing research in pediatrics - registration of the detainees caused by the acoustic emission of the snail (Fig. 27). We are talking about extremely weak sound oscillations generated by snail, which can be registered in the outer hearing aisle with the help of a highly sensitive and low noise microphone. Essentially, this is how the echo of sound served in the ear. Acoustic emission reflects the functional ability of external hair cortiyev organic cells. The method is very simple, it can be used for mass surveys of hearing already starting with the 3-4 days of the child's life. The study takes a few minutes, and the sensitivity is high enough.
Thus, electrophysiological methods for determining the hearing function remain the most important, and sometimes the only option for a similar study of hearing in children in children of newborn, chest and early children's age and are currently becoming increasingly distributed in medical institutions.
In case of inspection, pay attention to the condition of the external auditory passage and the eardrum. Carefully examine the cavity of the nose, the nasopharynk, the upper respiratory tract and evaluate the functions of the cranial nerves. Conductive and neurosensory touginess should be differentiated by comparing the hearing thresholds during air and bone conductivity. Air conduction is examined when transmitting irritation by air. Adequate air conduction is ensured by the permeability of the external auditory passage, the integrity of the middle and internal ear, the vestibular cholear nerve and the central departments of the auditory analyzer. To study the bone conductivity to the head of the patient, an oscillator or aktarton is applied. In the case of bone conductivity, the sound waves bypass the outer hearing pass and the middle ear. Thus, bone conduction reflects the integrity of the inner ear, snelled nerve and central conductive paths of the auditory analyzer. If there is an increase in air conduction thresholds at normal threshold values bone conductivity, then the defeat that caused the hearing loss is localized in the outer hearing aisle or middle ear. If there is an increase in the thresholds of the sensitivity of the air and bone conduction, then the lesion is in the inner ear, snail nerves or the central hearing analyzer departments. Sometimes the conductive and neurosensory hearing loss are observed simultaneously, in this case the thresholds of both air and bone conduction will be increased, but the air conduction thresholds will be significantly higher than bone.
With differential diagnosis of conductive and neurosensory hearing loss, Weber and Rinne samples are used. Weber sample lies in the fact that the feet of the tortone is installed on the head of the patient along the midline and ask it if it hears the sound of the camera evenly on both sides, or on one side of the sound is perceived stronger. With one-sided conductive hearing loss, the sound is more perceived on the lesion side. With one-sided neurosensory hearing loss, the sound is more perceived on a healthy side. Rinne breaks compare the perception of sound by air and bone conductivity. Kamerton's branches are brought to the auditory passage, and then the leg of the sounding tape is installed on a cottage process. The patient is asked to determine, in which case the sound is transmitted stronger by means of bone or air conduction. Normally, the sound is felt louder with air conduction than with bone. In case of conductive hearing loss, the sound of the chamberon mounted on a large-part process is better perceived; With neurosensory hearing loss, both types of conductivity are violated, however, during the study of air conductivity, the sound is perceived louder than normal. Weber and Rinne sample results make it possible to conclude on the presence of conductive or neurosensory hearing loss.
The quantitative assessment of the hearing loss is carried out using an audiometer - an electrical instrument that allows you to explore the air and bone conductivity using sound signals of various frequency and intensity. Studies are carried out in a special room with sound insulation coating. In order for the patient's responses to be based only on sensations from the studied ear, the other ear is shielded using wide noise. Use frequencies from 250 to 8000 Hz. The degree of changes in the auditory sensitivity is expressed in decibels. Decibel (DB) is equal to tenfect value of the decimal logarithm of the sound strength required to achieve the threshold in this patient, to the power of the sound required to achieve a hearing threshold from healthy man. Audiogram is a curve that displays the deviations of the hearing thresholds from normal (in dB) for different sound frequencies.
The nature of the audiogram for hearing loss is often diagnostic. With conductive hearing loss, a rather uniform increase in thresholds is usually detected for all frequencies. For conductive hearing loss with massive volumetric exposure, as it happens in the presence of a transudate in the middle ear, a significant increase in conductivity thresholds for high frequencies is characterized. In the case of conductive hearing loss caused by the staglessness of the conducting formations of the middle ear, for example, due to the fixation of the foundation of the tears at the early stage of the otoscolerosis, a more pronounced increase in the conductivity thresholds of low frequencies are noted. With neurosensory hearing loss as a whole, there is a tendency to a more pronounced increase in the high frequency air conduction thresholds. The exception is heaviness due to noise injury, in which the greatest decline in hearing is noted at the frequency of 4000 Hz, as well as the disease of the Menieret, especially at an early stage, when low-frequency conductivity thresholds are more significantly increased.
Additional data allows you to get speech audiometry. This method using doubled words with uniform stress on each syllable is investigated by a sponewaic threshold, i.e. the intensity of the sound at which it becomes a legible. The intensity of the sound in which the patient can understand and repeat 50% of words, is called a spongueic threshold, it is usually approaching the average speech frequency threshold (500, 1000, 2000 Hz). After determining the sponucleic threshold, the discriminatory ability is investigated using single-strokes with sound volume by 25-40 dB above the spongederal threshold. People with normal hearing can correctly repeat from 90 to 100% of words. Patients with conductive hearing loss are also well performing a discriminatory sample. Patients with neurosensory hearing loss are not able to distinguish the words due to damage to the peripheral department of the auditory analyzer at the level of the inner ear or snellest nerve. With the defeat of the inner ear, discriminatory ability is reduced and is usually 50-80% of the norm, whereas the ability to distinguish words significantly deteriorates and ranges from 0 to 50%.
Then, to determine the sensitivity to an increase in the intensity of sound, the intelligibility of speech should be analyzed at the intensity of the sound, by 25-40 dB exceeding the spongede threshold. A decrease in speech intelligibility with a greater intensity of sound indicates a damage to the snipigious nerve or the central departments of the auditory dialyzer.
When tympanometry, the acoustic impedance of the middle ear is estimated. The sound source and the microphone are introduced into the auditory passage and hermetically closed with its valve. The sound passing through the middle ear or reflected from it is measured using a microphone. With conductive hearing loss, the sound is reflected more intense than normal. The pressure in the auditory pass may increase and decrease depending on the atmospheric pressure. Normally, the second ear is most exposed to atmospheric pressure. With negative pressure in the middle ear, as it happens in the case of blockage evstarchy pipe, the moment of maximum stretching occurs when it occurs negative pressure In the outer hearing aisle. The violation of the integrity of the hearing bone complex leads to the fact that the maximum stretching point cannot be achieved. The tympanometry is particularly informative in the diagnosis of medium-sized diseases, accompanied by the allocation of a significant amount of transudate, in children.
With a tympanometry, an intense sound (80 dB above the hearing threshold) causes a reduction in the stirrup muscle. Reducing the aspiring muscle allows you to identify the change in the extensibility of the middle ear. According to the presence or absence of this acoustic reflex determine the localization of the lesion focus in the case of paralysis facial nerveAnd according to the presence or absence of the disappearance of acoustic reflex, the differential diagnosis of sensory and neural hearing loss is carried out. With neural hearing loss, the acoustic reflex decreases or disappears with time.
The minimum audiological study required to evaluate the patient with hearing loss should include the definition of the thresholds of the air and bone conductivity, spongueic threshold, the intelligibility of speech, sensitivity to increasing the intensity of sound, conducting a tympanometry, a study of acoustic reflexes and the disappearance test of acoustic reflex. These data allow you to comprehensively assess the functions of the auditory analyzer and determine the need for further differential diagnosis of sensory and neural tightness.
In addition to these samples, substantial assistance in the differential diagnosis of sensory and neural hearing loss can have a study of the phenomenon aligning the sound volume, the test determination test to the rapidly small increment of the intensity of the sound, the test of the disappearance of the threshold Yuna, the bekeshi audiometry and auditory stem caused potentials.
Clinical evaluation of hearing loss complaints. In patients with hearing loss complaints, it is necessary to identify the accompanying symptoms, such as noise in ears, systemic dizziness, surroundings, sinking and swelling of the ear. In addition, it is necessary to carefully restore the sequence of the rumor reduction process. The sudden appearance of one-sided deafness with the noise in ears or without it may indicate the viral defeat of the inner ear. A gradual decrease in hearing is characteristic of the otosclerosis, the scums of the auditory nerve and the disease Meniere. In the latter case, intelligible noise in ears and dizziness are usually arise. Deafness can develop in demyelinizing lesions of the brain barrel. Headowing is characteristic sign Some hereditary diseases. In some cases, it is celebrated from the moment of birth, in others it occurs in a children's or adolescence.
The noise in the ears is called the feeling of sound in the absence of such in the environment. It can be a buzzing, roaring, ringing but character pulsating (synchronous with heartbeat). The noise in the ears is usually observed in combination with conductive or neurosensory hearing loss. Pathophysiological mechanisms of noise in the ears are not well studied. The reason for its appearance can be established by finding out the origin of the concomitant reduction of hearing. The noise in the ears may be the first symptom of the formidable disease, such as acoustic neurine. When pulsating noise must be examined vascular system Heads to eliminate the tumor of the vessel, for example, the gomboms of the jugular vein, aneurysm or the occasional lesion.
Most patients with conductive and unilateral, or asymmetric, neurosensory hearing loss must be carried out by CT studies of temporal bone. In patients with neurosensory hearing loss, the vestibular system should be examined using electronistagmography and caloric samples.
Impedanceometry - a study method based on measuring the acoustic resistance (or acoustic adhesiveness) of sound conductive structures of the peripheral part of the auditory analyzer. In clinical practice, two techniques of impedanceometry are most often used - tympanometry and acoustic reflexometry.
Tympanometry allows you to estimate the mobility of the eardrum and auditory bones. This is a quick and non-invasive method for the diagnosis of such diseases as an exudative (secretory) average otitis, otosclerosis, etc.
With the help of acoustic reflexometry, you can register a reduction in the internal muscles in response to sound stimulation. The method is used to differential diagnosis of diseases of the middle and internal ear, as well as to determine the discount thresholds used in the selection and configuration. hearing aids.
Multi-frequency acoustic impedanceometry is a precision technique, which allows measuring the resonant frequency of the middle ear. It is successfully used in the comprehensive diagnosis of anomalies for the development of auditory bones, differential diagnostics. The results of multi-frequency impedanceometry are used in the process of performing operation. cochlear implantation.
The hearing body is one of the main analyzers providing a human connection with the environment. To date, modern otolaryngology is treating a number of different violations by this sense body. However, correct therapy may be selected only after a complete and adequate examination, which is necessarily performed under the control of a highly specialized specialist.
The first diagnostic search of the doctor begins simultaneously with the familiarization with the complaints of the patient, as well as with the history of the development of the disease. Methods for possible studies under different states are very diverse, which mainly depends on the specifics of the disease and the age of the patient.
Distinguish two main directions in diagnostics - these are subjective and objective methods Survey of hearing. They are equally used in people of different age groups, but the survey of hearing in children has its own characteristics.
So, early age for evaluating auditory perceptions, unconditionally and conditionaloreflex research techniques are prescribed. In cases of proper execution, they are informative enough.
Unconditional reflexive way
A fairly common method of evaluating hearing in newborns, which is based on the response of the child to the sound irritant. This reaction is formed without any preliminary preparations. These include reflexes:
- Bekhtereva - reacting to sound, the child begins to flash hard, the activity of the eyelids increases.
- Shurygin - in a child against the background of the presence of a sound stimulus expands the pupil.
- Sucking and gladation.
- Increase the frequency of breathing and heartbeat.
- Strengthening motor activity in the limbs.
In addition to the above reactions, in response to a loud sound, the baby can often occur fright, fading or awakening, and a variety of grimaces on the face appear.
Despite the availability and ease of use, this technique has a number of flaws:
- For each kid is characterized by its own, individual reaction to the stimulus.
- When repeated check, there is a decrease in reflex.
- To appear the reaction, it is necessary to effect a sufficiently high sound threshold, which worsens the detection of hearing impairment to 50 or 60 dB.
Such a hearing diagnosis in children is uninformative if the child has concomitant pathology from the nervous system.
ConditionalFlex method
This method is successfully applicable only in the next limits of childhood - from year to three years, since in the older age group There is no more interest, and the smallest fatigue was noted at the smallest.
It is based on the formation of the conditional reflex during the repeated repetition of the sound signal against the background of unconditional reflexes - defensive, food (the basis of Pavlov's theory).
Most often, the child appears pupil, blinking and vascular reaction. Also, the method has its own list of shortcomings: when repetition, the reflex is quickly fading, it is impossible to accurately identify the threshold of hearingness.
In children with mental disorders, such a type of diagnosis is very difficult. It is quite informative subjective methods that include a tonal audiometry, but since it is applied in children over seven years old, the spread in the younger group received gaming audiometry.
Game audiometry is a subjective study of hearing in children since a three-year-old age. The child demonstrate the toy or the image, reinforcing this action by sound accompaniment, as a result of which the reflex reaction is achieved to the beep.
To prevent the extinction of the resulting reflex, it is necessary to replace the pictures or toys used. The sound volume also needs to be reduced, which allows you to analyze hearing according to a full tone scale.
The obtained data is stored on the audiogram - a graphic image showing the connection between the hearing of hearing and the intensity of the sound and the evaluation of the hearing conductivity.
Diagnosis of central hearing changes in children
In many cases, a child with a physiological hearing threshold and intelligence can identify the presence of disorders in the ability to distinguish between the bell and deaf consonants, remembering the order of sounds, in the electoral misunderstanding of oral speech. These signs are characteristic of central violations by the hearing body. To diagnose them, the following hearing research methods are carried out:
- Dichotic test. It has many variations. The basis of the method consists in simultaneously exposure to both Ears of two completely different speech signals. This allows you to identify violations by the cortical departments and determine the affected side.
- Monaural test. In contrast to the dichotic test, the speech signal is fed sequentially. The method is used to identify disorders from the brain barrel.
Tests are also used that give an estimate of the perception of the time structure of the signal, which in addition to identifying pathology from the cortical departments, makes it possible to determine the maturity of the auditory pathways.
Subjective evaluation of hearing organs
From two years of age, it is permissible to test the hearing to use the same approach in the examination of both adults and children. However, it becomes possible only if the child began to take speech development by this time - it is already able to repeat the words or indicate their visual image in the pictures. Thus, in addition to the above surveys, it is permissible to conduct subjective hearing research methods in the form of a whisper speech.
This diagnostic method is based on a person's skill to recognize various speech signals while at the same time six meters from the sound source. In the process of studying the subject, placed in a relatively soundproofed room, having it in such a way that one ear is directed towards the sound source, and the other time is covered.
Usually, two-digit numbers or specially selected words are used, with a list of which you can find in Table V. Voyachek. The results obtained may indicate the level of violations identified. For example, violations from the sound-by-penetrating device can be revealed if a person does not perceive a whisper speech, and the colloquial is pretty good.
If the surveyed is noted a degraded perception of phrases, but a normal understanding of simple sounds remains, then one can judge the presence of violations in the zone of hearing centers.
There are other subjective ways to survey the hearing of children and adults, which include the use of special tools - Tambleton. With their help, it is possible to evaluate the air and bone conductivity of the sound, which, in turn, allows you to judge the quality of the functional ability of the organ of hearing. A quantitative assessment is given on the basis of the time for which the surveyed perceives the sound signals from irritated chamberon.
It is this method of diagnostics that makes it possible to clarify the cause of changes from the hearing function in the hearing impaired: whether it is a damage to the sound (impaired the perception of low tones) or a sound susceptible (deterioration of high tones perception) of the device.
Taking into account the period of adaptation and fatigue of the body, the working tape is made to the ear no more than 5-10 seconds and are attributed for the same time.
Ocacoustic emission
Despite the fact that subjective diagnostic methods are widely used, high popularity, due to their high informativeness and accuracy, won precisely objective methods of hearing research.
One such species of this diagnosis, which is carried out for the purpose of mass screening and is applied at the initial stages of the survey, is the method of an open-acoustic emission (UAE).
In the area of \u200b\u200bthe external passage, a miniature microphone is placed, registering a weak sound, which arises due to the motor activity of external hairs cells of the Cortis organ. If hearing is reduced by more than 25-30 dB in accordance with normal values, then this weak sound is unable to register during the study.
The spontaneous UAE differ, which is recorded without conducting acoustic stimulation and the UAE caused by an acoustic stimulus (short, single tonal or two purebredonal). The characteristics of the UAE caused by the age of the surveyed.
The study has I. negative side - A amplitude of the UAE decreases when exposed to high noise. However, this method allows you to establish only the very fact of reducing hearing, and not to detail the level and degree of degradation.
Acoustic impedanceometry
Acoustic impedance allows you to register the pressure numbers in the middle ear, identify the presence of fluid and damage in the eardrum, in the connection of the auditory bones. The method is based on the measurement of resistance, which is external and medium departments Ear in response to a beep.
The obtained low values \u200b\u200bof the acoustic impedance correspond to physiological indicators, any deviation from the norm always indicates the presence of disorders from the middle ear and the eardrum. In addition, the method includes a dynamic measurement of the devotee of the eardrum (tympanometry), as well as the registration of the reflex reduction of the stirrup muscle.
If the acoustic reflex is within 75-80 dB, this indicates the absence of violations by the sound system. Its negative values \u200b\u200bare often detected during otitis, accompanied by the accumulation of fluid, the inflammation of the Eustachius pipe.
To obtain reliable data, it is necessary to take into account the state of a person during a survey - the presence of disorders from the nervous system, the reception of sedative drugs, as well as to evaluate according to the age of a person.
Computer audiometry
All previously described methods for diagnosing hearing disorders are inferior by their informative. this kind Research. They begin to conduct a survey with the introduction of a patient into a state of drug sleep, since the procedure lasts for quite a long time. Such diagnostics can be carried out in children who have reached a three-year-old age.
The method is based on the registration of the electrical activity of the hearing system, which arises in different parts of the hearing body, as a reaction to the sound stimulus. There are four grades of registered caused potentials: barrel, medium and longlaten (cortical), as well as snail potential.
Electrocookhloeography gives an assessment of the state of the peripheral hearing body. Most often, this method is prescribed if there is a suspicion of the hydrops of the labyrinth, as well as as a basic examination with intraoperative observation. Correspondent potentials display the reaction of the brain cortex on the beep, and the short-prophent - brain barrel.
This method is actively used in the diagnosis. pathological conditions Organ hearing in childhood. Electrical potentials are significantly complemented by other methods of information about the characteristics of violations from the hearing aid.
The complexity of this study consists only in the necessary preliminary sedation of the surveyed.
At the moment, this diagnostic method is applied only in specialized centers, since it needs good equipment and in the work of highly qualified specialists.