This paper is a comparative study of the early and late functional results of tympanoplastic operations, as modified by Khan. Following such surgery, we examined 494 patients who had been operated on between 1970--1972 in the ENT Clinic of the Free University of Berlin (Klinikum Westend). Preliminary and final hearing results were recorded with the aid of sound audiograms, which were critically assessed by two different types of evaluations. These included the results of pure-tone changes and speech reception thresholds as achieved by the tympanoplastic operations. On the basis of socially useful hearing improvements, the functional results of cases operated in our clinic are above average. The hearing gain shown from post-operative controls to the final studies is especially satisfactory, since this also includes an improvement in bone conduction.