Tympanic Membrane Perforation: Effect on Audiogram

Abstract

The effects of both size and location of tympanic membrane perforations on hearing loss were studied. Using only those cases in which the air-bone gap was closed by myringoplasty, the variable of ossicular chain defects was controlled. Definite trends appeared in averages of the groups which tend to confirm two generalizations: (1) Effectiveness of the tympanic membrane decreases with loss of total area and (2) loss of membrane contact with the manubrium of the malleus affects its abiliy to move. A useful formula for predicting hearing loss on the basis of size and location of perforation is impossible because of wide variations of individual cases within any particular group.