Methods of hearing testing and research

Otolaryngologists perform a hearing test using the method most suitable for a specific patient in any questionable situation. The modern equipment used by our doctors ensures high accuracy and informativeness of the result.

Hearing diagnostics

Hearing research methods are divided into large groups - subjective and objective.

Subjective or psychoacoustic:

• hearing test using speech;
• tuning fork diagnostics;
• tone audiometry

Objective:

• computer audiometry;
• tympanometry;
• acoustic reflectometry;
• otoacoustic emission.

Unconditional reflex and conditioned reflex reactions of the patient to sounds can also be attributed to the objective methods of hearing research.

Unconditional reflexive techniques

Easily available for use, often used in the screening examination of hearing in children in the first 12 months of life. These are unconditional reflexes, the most informative of which are:

1. dilation of the pupil;
2. eyelid activity;
3. oculomotor reflex;
4. opening eyes;
5. freezing or shivering;
6. turning the head towards the sound source;
7. awakening;
8. activation of movements;
9. change in frequency, arrhythmia of respiratory movements, contraction of the heart.

These methods of studying the organ of hearing also have disadvantages:

low accuracy (a wide range of reactions to a sound stimulus is possible in children of the same age);

if the sound is repeated, the reflex is extinguished;

allow to suspect only severe hearing impairment.

Infants with suspected hearing loss must undergo additional examinations using instrumental diagnostic methods.

Conditioned reflex methods

Also used in pediatric practice, informative for young children - from one to three years.

The essence of these methods is to develop conditioned reflexes in the subject as a reaction to a sound stimulus created by the doctor with repeated unconditional reinforcement. They include defensive, operant, food conditioned reflexes, blinking, pupil, vascular conditioned reflex reaction.

The results of the study of hearing disorders by assessing the conditioned reflex reactions of the child are imprecise - they directly depend on the psycho-emotional state of the examinee, are uninformative in patients with mental disorders that do not allow to accurately determine the hearing threshold. When re-diagnosed, these reflexes quickly disappear.

They are based on the evaluation of the test of the quality of sound perception. The advantage of these methods is their simplicity and availability, the absence of the need to use complex equipment for diagnosis. Minus - the result depends on the patient's words and can be falsified.

As subjective methods of hearing research are used:

• diagnosis of hearing in language;
• tuning fork examination of the organ of hearing;
• tonal audiometry.

Speech research

The diagnostician calls out simple words or numbers at different volumes at different distances from the patient's ear. Normal hearing allows you to hear a whisper from a distance of 6 meters. If the patient does not hear the whisper from this distance, the doctor comes a little closer and repeats what was said. When the patient reports hearing, the doctor notes the distance in the hearing passport. If the patient does not hear a whisper, diagnosis is carried out with spoken, and then with loud speech. The patient closes the unexamined ear on his own by pressing the ear.

Tuning research

When studying the quality of hearing with the help of tuning forks, two of the eight devices in the set are mainly used, evaluating the result taking into account the standards. Standards are the time during which patients with normal hearing hear the sound of a tuning fork.

The method makes it possible to detect the fact of hearing loss and to determine which type of hearing loss - sensorineural or conductive - occurs in this patient.

The result of the study is entered in the auditory passport.

Audiometry

The most common methods of subjective audiometry are tonal threshold and suprathreshold audiometry.

An audiometer is used - a device that synthesizes sounds of different intensities and frequencies, which makes it possible to determine the hearing threshold - the minimum sound intensity of a given frequency, which is determined by the patient's healthy ear. After hearing the sound, the patient must press the remote control button or talk about it. The result of the diagnosis is a graph where the sound intensity is marked on the horizontal axis. and its frequency along the vertical line. The research makes it possible to verify the form of deafness - to determine whether it is conductive, sensorineural or mixed.

Objective methods of research of the organ of hearing

They are used more often in children, as well as in adults with suspicion of simulation, the psychogenic nature of hearing loss, which presents complaints of pronounced tinnitus.

Computer audiometry

The method is based on the registration of auditory evoked potentials in the brain in response to the impact of an auditory stimulus of different intensity and frequency. Bioelectric impulses are recorded using electrodes located on the patient's head - electroencephalography.

The price of an objective audiological examination of hearing is higher than the price of tonal audiometry. However, this method of diagnosis is highly informative - it helps to determine the acuity of hearing, when it decreases, it is possible to identify the localization of the pathological process.

The basis of the method is the registration of the resistance encountered by the sound, spreading through the organ of hearing at different air pressures in the outer ear.

The result of the study is displayed in the form of a graph - a tympanogram, on the basis of which the doctor will draw a conclusion about the state of the structures of the middle ear.

Acoustic reflectometry

The muscles of the tympanic cavity, straining, reduce the amplitude of the auditory ossicles, which is necessary to protect the inner ear from acoustic injuries.

Intense sound stimulation leads to a reflex impulse - the muscles of the tympanic cavity contract. The moment of this contraction is called the threshold of the acoustic reflex and is registered with a special device. Normally, it is 80 dB higher than the sensitivity threshold of a particular patient. Instrumental determination of the threshold of the acoustic reflex allows you to calculate the threshold of individual sensitivity, which is absent on both sides when the hearing is impaired.

Early diagnosis of hearing disorders is very important. Patients who suffer from its decrease experience difficulties in communication, learn more slowly, have difficulty making new social connections, due to which they gradually distance themselves from society. Timely verification of the problem is the first step on the way to its solution. You should consult a doctor for a hearing test at the first suspicion of hearing loss.