The effect of body mass index to resonance frequency of middle ear

Whether the classic tympanometry is sufficent for the assessment of acoustic properties of middle ear has been a debate issue. In classic tympanometries, 226 Hz is frequently utilized as probe tone. Through providing the analyses of tymponagrams reaped between 226 Hz and 2000 Hz, multifrequency tympanometry is an adventageous test battery that can assess the resistance and permeability of middle ear in a wide range. Multifrequency tympanometry provides parameters through parsing tympanum admittance and its elements. One of the significant parameters supplied by the multifrequency tympanometry is resonant frequency (RF). Resonance frequency, allowing maximum movement with minimum energy and maximum frequency of the tympanic membrane sound energy can be transmitted by the middle ear to the cochlea. In case of the presence of specific pathologies, resonant frequency values can be lower or higher compared to healthy and normal ears. Although multifrequency tympanometry is a favourable test, it has not been clinically utilized around the world as in the case of our country. The reason behind the lackness of widespread use of multifrequency tympanometry is the absence of sufficent data in this scientific literature of this field. In accordance with this purpose, to provide a novel information to the literature, in relation with body mass index, whether the resonance frequency of the middle ear changes or not; and if so, its extent has been studied. In this study, 78 volunteers (156 ears) have taken place as participants who does not have any hearing loss only having normal autoscopic conditions at the Otorhinolaryngology Department and Audiology, Speech and Voice Disorders Unit of Baskent University. Following the autoscopic examination by an otolarygologist, participants' sound thresholds are measured by benefiting pure tone audiometry and then their immitancemetric measurements have been fulfilled. Immitancemetric measurements of the participants have been performed using Grason Stadler (GSI) Tympstar Version 2 electro-acoustic immitancemeter. Resonance frequency differences obtained from all of the participants (156 ears) have been taken into evaluation. According to their BMIs, the resonance frequency of participants, trichotomized as <18,5 kg/m2, 18,5-24,9 kg/m2, >25 kg/m2, have been studied. It has been found out that people who have BMI <18,5 kg/m2 have a resonance frequency average as 823,08±86,58, while the people who are between BMI 18,5 and 24,9 kg/m2 have a resonance frequency average as 817,31±94,91 and finally people have BMI >25 kg/m2 have a resonance frequency average as 771,15±112,61. Although no meaningful resonance frequency difference has been found out on people who have BMI <18,5 kg/m2, 18,5-24,9 kg/m2; a meaningful difference has been spotted on people having BMI <18,5 kg/m2 / BMI >25 kg/m2 and 18,5-24,9 kg/m2 / BMI >25 kg/m2. In light of data provided, BMI data should be taken into notice of the people whose middle ear resonance frequency values are examined.