The Normal Function of the Eustachian Tube: A Study of 102 Cases

Abstract

A method permitting quantitative tubal function tests across an intact tympanic membrane has been worked out. The method permits a continuous recording of the volume deviation of the drum in relation to the neutral position both at changes of the ambient pressure and changes of the pressure in the middle ear. Repeated testings have been performed on 102 cases with normal ears which all had normal hearing, i.e. a normal audiogram, and normal ear findings. 64 % could equilibrate under dynamic pressure conditions, i.e. simulated descent, 84 % could propagate a square wave pressure from the rhinopharynx to the ear and 79 % had a positive Toynbee's test. 12 % could equilibrate negative ear pressures completely while the rest have a reduced capacity to equilibrate or none at all, though the ears were regarded as normal. The findings are discussed.