慢性中耳炎における聴力の変動

HEARING THRESHOLD CHANGES THAT OCCUR IN CASES OF CHRONIC OTITIS MEDIA

　Ⅰ．緒言

　慢性中耳炎の手術例において，術後に域値の下降が認められたとしても，果してそれが真の聴力の改善を意味しているものか否かを知るためには，慢性中耳炎における聴力の自然変動を考慮に入れる必要がある。正常者における聴力変動については，すでに多くの研究報告があつて，その大要はわかつているが，慢性中耳炎という疾患が存在する場合には，正常者の資料をそのまま参考にしてよいか否かには，なお疑問がある。今回著者は，保存的療法のみを行なつた慢性中耳炎耳における聴力の長期間変動について，そのオージオグラムに考察を加えてみた。

　Changes in hearing threshold that may arise in cases of chronic otitis media are studied. Audiograms are recorded on the patient with an interval ranging from 1 to 3 months apart and these are statistically analysed.

　The material of this study consisted of 69 cases of chronic otitis media who were not treated surgically. Fifty four normal subjects were included for controls. Following conclusions are made:

　(1) The range of hearing level changes in cases of chronic otitis media appeared to be somewhat larger than those with normal cars, in both air and bone conduction hearing.

　(2) The range of hearing level changes that occur in bone conduction is some-larger than that of the air conduction in both cases, the affected and the normal.

　(3) The above facts should be taken into consideration when evaluation of the hearing results of the tympanoplastic operation is sought.