Determination of Resonant Frequencies of an Acoustical System of the Human by Means of Objective Methods of a Research of Hearing

Different pathological processes lead to changes of human auditory system characteristics. Nowadays, hearing diagnosis is not surprising and does not cause unnecessary questions, because most people understand the importance of health care and know about problems that can arise if they are not warned in advance. In the world there are many methods and programs for objective diagnosis of human hearing. Today, among hearing diagnosing objective methods, multifrequency acoustic impedancemetry and otoacoustic emission are most widely used in clinical practice. Comparison of the obtained characteristics in normal and pathological conditions allows us to judge the degree of changes in the auditory organ and diagnose some of its diseases. However, a large discrepancy between intersubject data may overlap deviations from norms. This is the main problem in diagnosis of hearing system. Determination the resonant frequency of human auditory system structural elements in a comprehensive study, using objective methods gives us a possibility to detect changes in ear conductive system more accurately. Significant changes in the resonance frequency of human middle ear make it possible to detect an existing pathology at a functional level. Resonant frequency shift (to one or the other side) may indicate the presence of otosclerosis, auditory ossicles chain break, etc. In this work, the parameters of the human middle ear were obtained theoretically, based on a two-circuit model of the human middle ear, and confirmed experimentally, using tympanometry and otoacoustic emission, which eliminate the main problem of hearing diagnostics and offer new diagnostic parameters for sound-conducting ear system diseases diagnosing, namely, value of resonant frequencies. Determining the resonant frequency of human auditory system structures in a comprehensive study using objective methods, allows us to identify changes in ear sound-conducting system. To study human auditory system resonant frequency, an electromechanical model of human middle ear was selected and its main parameters were determined: eardrum and tympanic cavity flexibility, acoustic impedance of air in the tympanic cavity and auditory tube, resonant frequency of first and second circuits of middle ear vibrating system, auditory ossicles weight. Purpose of the study - to search and identify effective ways to improve objective acoustic diagnostic methods and substantiate the choice of tympanometry and otoacoustic emission as the main methods for studying the state of the human auditory system, which allow a detailed assessment of pathological processes. Ref. 10, fig. 2, tabl. 1.`