Acoustic impedancemetry is a set of diagnostic procedures that are carried out to assess the state of the middle ear, which is responsible for the transmission of sound air vibrations, as reported by the online publication for girls and women from 14 to 35 years old Pannochka. net The anatomy of the ear is designed in such a way that the existing auditory reflex plays the role of a protective mechanism: under the influence of strong sound vibrations, the muscles of the tympanic cavity tense up, the chain of the auditory ossicles and the tympanic membrane is deformed and resistance to sound vibrations arises, protecting sensitive hair cells. Impedancemetry makes it possible to check the degree of this resistance. Based on acoustic stimulation of the middle ear, impedancemetry allows you to objectively assess the condition of the tympanic membrane, auditory tubes and bones, pressure in the middle ear, find out if there are scars or fluid in the middle ear cavity.
In addition, ear impedancemetry makes it possible to fix the contraction of the auditory muscles and assess the threshold of the acoustic reflex, including. threshold of discomfort, differentiate diseases of the inner and middle ear: otitis, tubo-otitis, otosclerosis, confirm or refute the disease of the auditory nerve.
Methods of impedancemetryEar impedancemetry includes tympanometry and the study of the auditory reflex.
The method of impedancemetry - tympanometry means checking the mobility of the tympanic membrane under air pressure in the auditory external canal. Tympanometry is prescribed for diseases of the adenoids, pathologies of the tympanic membrane and auditory tubes, diseases of the middle ear, hearing loss, after suffering otitis.
An audiologist conducts tympanometry after examining the ears, removing sulfuric masses (if necessary) and explaining to the patient the essence of the test. This procedure of impedancemetry goes as follows: the doctor inserts a small rubber probe into the ear canal and turns on the device - the impedancemeter, which, using a special pump, changes the pressure in the ear and makes the eardrum move. The pressure in the ear canal is measured using a small microphone connected to a probe inserted into the ear.. The procedure is painless, the patient feels the same pressure in the ear as when climbing mountains or during an air flight, and hears a squeak. Do not chew, move or talk during the acoustic test. Tympanometry lasts only 5-10 minutes, the audiologist receives the results instantly to analyze the patient's condition.
The second method of impedancemetry - the study of the auditory reflex, is based on the supply of a loud sound stimulus to the ear.. Sound is delivered directly into the ear canal, through an earpiece, earpiece or probe. The stimulus passes through the middle ear, reaches the cochlea. From here, information about the intensity and frequency of sound is transmitted to the brain stem through the eighth nerve, where the sufficiency of the intensity of the sound stimulus for a reflex response is determined.. With sufficient intensity, a two-way reflex response occurs: the impulse passes along the seventh nerve from both sides to the muscles of the stirrup and causes them to contract. The sound stimulus for the study of the reflex is 85 dB in one ear.
If there is no reflex response, the volume level is increased gradually, by 10 dB, until a reflex response occurs - the stirrup muscles will contract by 0.05 cm.
Acoustic impedancemetry is used not only for the diagnosis of ear diseases and hearing pathologies, but also for the selection of a hearing aid, cochlear implantation. In these cases, the examination of the condition of the middle ear is combined with pure tone audiometry.. Ear impedancemetry is also used for control examination in the treatment of myasthenia gravis and facial paralysis.
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