We study audiometric parameters including Transient Otoacoustic emissions, pure-tone audiometry for air- and bone-conduction, and spondaic speech recognition thresholds for air- and bone conduction in a pre- and postoperative situation in patients due for surgery for tympanic membrane perforations and otosclerosis. The hypotheses are that the precision of the preoperative assessment may be increased, and our knowledge about the effect on the inner ear by middle ear surgery may be increased.