The effect of body mass index on traditional 226 Hz tympanometry and wideband tympanometry test results

Objectives: The aim of this study was to investigate the possible effects of body mass index (BMI) on traditional 226 Hz tympanometry and wideband tympanometry (WBT) to gain a better understanding of resonance frequency. Patients and Methods: A total of 158 ears of 79 volunteers (19 males, 60 females; mean age: 20.5 years; range, 18 to 27 years) who had normal hearing and normal otoscopic examination findings were included in the study between October 2019 and June 2020. By measuring the weight and height of the participants, their BMI values were classified into three groups: ?18.5 kg/m2 (underweight), 18.5 to 24.9 kg/m2 (normal weight), and ?25.0 kg/m2 (overweight). Tympanometric evaluations were conducted using the Interacoustics-Titan WBT. Results: The difference of ear canal volume (ECV) was significant between the two sexes (p<0.05), while there was no significant difference in the tympanometric peak pressure, compliance, gradient, and resonance frequency between the sexes (p>0.05). A significant difference was found in the ECV and resonance frequency among the three BMI groups (p<0.05). Accordingly, as the BMI increased, the ECV increased and the resonance frequency decreased (p<0.05). Conclusion: The BMI may affect ECV and resonance frequency values which should be considered during the examination.