Abstract
The thickness of the tympanic membrane was measured under a microscope, using human serial horizontal sections of 96 normal temporal bones from 78 subjects. Ten different sites of the tympanic membrane were chosen for measurement, and the average of thickness was compared for each site. Tympanic membranes were grouped according to the subject's age into ten-year intervals, and their thickness was measured. The thickest site was the mid point between the short process and the posterior edge, because the lamina propria was remarkably thicker. There was almost no difference in the thickness of the tympanic membrane among the various age groups.
