Observations on Tympanic Membrane Perforations (Safe Type) and Hearing Loss

Abstract

The most commonly observed clinical findings in otological practice is discharging ear in which perforation of the tympanic membrane is the commonest, yet the patients hardly ever seek advice for deafness as the presenting symptom. In patients with the symptoms of ear ache or ear discharge when relieved seldom present for follow up and are not very much concerned about the hearing loss present there. There is a different correlation between surface area of tympanic membrane and amplification of sound. Conductive hearing loss is seen in lower tones than higher tones. When the surface area of tympanic membrane is reduced in case of perforations there is decreased in amplification of sound waves. Hearing loss is less in smaller perforations than in larger ones and more for lower tones than for higher tones. A perforation has more serious effect on hearing when it is located in the vicinity of the attachment of malleus. Perforations situated in the postero-inferior quadrant will cause more hearing loss than in other quadrants. The aim of the study is to know the exact location and exact size of perforation and to make a comparative study on the amount of hearing loss produced respectively—in cases of central perforations. Data of 100 patients was collected and studied from May 2015 to April 2016. Hearing loss is related to site and size of perforation with postero-inferior quadrant perforations caising more degree of hearing loss. It varies between 2 and 25 dB more at lower 2 frequencies. Hearing loss is related to size and site of perforation. Small perforation in the postero-inferior quadrant cause more hearing loss than a perforation of same size in other quadrants. Similarly the size of perforation also affects the amount of hearing loss.