Multifrequency Tympanometry Case Study

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MULTIFREQUENCY- MULTICOMPONENT TYMAPNOMETRY IN NORMAL HEARING ADULTS

Abstract

Multifrequency tympanometry refers to testing middle ear function at higher frequency(678,1000Hz) where as Multicomponent refers to measuring middle ear function for various components(Y,B,G). middle ear function varies with frequency and is capable of distinguishing subtle acoustical changes in the middle ear system hence the main application of MFT is in cases with low impedance pathologies such as ossicular chain discontinuity, hypermobile Tympanic membrane etc. The conventional tympanometry fails to differentiate the presence of mass dominated pathology. Current study aimed to develop Indian norms within the age range of 18 to 65 years. 267 males and 243 females were taken as subject. Calibrated GSI tympstar impedance audiometer was used to measure Y, B, G components at 226 678, 1KHz . Results of study indicated that variable patterns of peaks were seen more frequently at higher frequencies compared to low frequencies. The obtained
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The resonant frequency is defined as the frequency at which the compliant and the mass susceptence are equal. Normal middle ear resonance falls between 800Hz to 1200Hz. Middle ear system is stiffness controlled above the resonant frequency and mass controlled below the resonant frequency. The third variable, friction, determines the absorption or dissipation of acoustic energy. In admittance terms, this element is called conductance and is denoted by Ga. It is defined as ability to pass sound energy in spite of friction. Conductance is plotted on the X-axis and is the only element that contributes to total admittance at the resonant frequency. The admittance correlate of acoustic resistance (Ra) is conductance (Ga) and it is dependent on the

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