Hearing loss in perforations of the tympanic membrane

70 patients with dry central perforations have been studied to assess the hearing loss. The hearing loss is greater at the lower frequencies and increases with the size of the perforation. Malleolar perforations cause more hearing loss than the non-malleolar unless the perforation involves less than 10 per cent of the tympanic membrane surface area. Perforations of the postero-inferior quadrant cause more hearing loss than those in the antero-inferior quadrant.