WBA in Individuals with Central and Marginal Type of Tympanic Membrane Perforation without Active Discharge

Abstract

Aim and Objectives: This study aims to examine the impact of two different types of tympanic membrane perforations (central and marginal) on WBA measures. Additionally, the study aims to compare the effects of central and marginal perforations with those of a normal ear, as well as to make a comparison between the two types of perforations. Methods: Two groups in the age range of 18 to 50 years were considered in the study. Group I consisted of ears with central perforation (n=65 ears), and Group II consisted of ears with marginal perforation (n=13 ears). Normative data were taken from the investigation of Karuppannan and Barman (2021). All the participants have undergone WBA measurements across frequencies in both pressure conditions. Results and Discussion: The WBA measured in Group I across the frequencies and the comparison with the normal ear group revealed a significant difference across all the frequencies. It shows a maximum WBA at 5000 Hz. Individuals with a central perforation displayed a significant decreased absorbance at low frequencies and increased absorbance at high frequencies compared to the control group with normal ears. WBA in Group II across the frequencies and its comparison with the normal ear group revealed a significant difference only at specific frequencies. WBA pattern shows three maxima at 600, 4000, and 6000 Hz and a significant dip at 2000 Hz. Individuals with marginal perforation exhibited near-normal absorbance at lower frequencies. In comparison between the central and marginal perforation, a significant difference was found only in a few frequencies. Central perforation showed lower absorbance than marginal perforation at lower frequencies and decreased absorbance for marginal perforation at mid and high frequencieses. All these findings could be due to the complexity of the tympanic membrane vibration pattern and also could be due to differences in wavelength of the different frequencies. Conclusion: The results of this study offer information about how the TM functions in transmitting sound and its clinical implications. By utilizing WBT to confirm what is observed during an ear examination, audiologists can guide patients. These measurements prove useful in distinguishing between normal ears and those with perforations, emphasizing their importance for diagnosis.