Since middle ear reconstruction began to be widely performed a number of different assessments of hearing results has been proposed. The criteria of Clinical Otology Japan (1987) is commonly used in Japan otherwise the post-operative air bone gap is used as a success rate in foreign countries.
In this paper we proposed a new concept of “Achievement Rate” as a hearing assessment which is represented “post-operative hearing gain/pre-operative air bone gap”. This parameter simply means the closing rate of the pre-operative air bone gap and also how much the surgeon contribute to the patient within the extent of pati ent's sensory neural ability.
Employing this method we made a retrospective study of 373 ears, tympanoplasty without ossiculoplasty in 27 ears, type 1 in 181 ears, type 3 in 151 ears, type 4 in 77 ears.
This study suggested that “Achievement Rate” is related to the post-operative air bone gap and postoperative hearing gain neither to pre-operative air conduction threshold nor pre-operative air bone gap. It was concluded that “Achievement Rate” might be usefful for concrete prediction of the post-operative hearing level and analysis of the operative efficacy.
