Opinions differ on the value of preoperative testing of tubal function. The results vary widely, but so far no comparative investigation between different tubal function tests seems to have been published. On 132 ears with central tympanic perforation, 9 of which were traumatic and the remaining following chronic otitis media, tubal function was studied with a closed manometric method and open flow volume method which measures the tubal volume passage. The results of the closed and open techniques agreed in 96%. The open method is more sensitive, but the closed method is easier. 70% of the total material had aspiration capacity, i.e. could neutralise middle ear pressures, which is better than earlier results. Toynbee's test is a good screening test and when positive, it means good tubal function. A close correlation was found between tubal function and the volume of the air cell system as an effect of the systemic mucosal damage.