幼小児の急性中耳炎治ゆ時の聴力検査成績およびティンパノグラムについて

Abstract

The hearing ability after healing from acute otitis media was tested in infants younger than 5 years. Those tested represented approximately half the number of cases of acute otitis media with repeated recurrence. Hearing abnormalities were recognized in about 30% of the 3 to 4 year-old infants in peep show tests.Although bone conduction acoumetry was difficult to perform in this age group, tympanometry was performed in 339 cases of infants aged 4-8 years. An attempt was made to find out if this hearing abnormality originated in conductive deafness or in attributable to measurement errors, peculiar to these infants. Tympanograms were obtained from 413 ears (82.4%) with normal hearing and 88 ears (17.6%) with abnormal hearing. These test revealed that 264 ears (63.9%) in the normal hearing group were A type representing more than half the number of cases, 2 ears, B type with 0.5% and 147 ears C type with 36.5%, while 41 ears in the abnormal hearing group were A type with 46.6%, 5 ears B type with 5.7% and 42 ears C type with 47.7%.Although it was natural that the total of B and C types often observed in tubal obstruction and middle ear diseases was larger than the A type in the normal group, the total of 27 ears of A type in the abnormal hearing groups of 4-year-old infants alone was higher than the total of B and C types, 22 ears. Thus, other than those with conductive deafness, abnormal levels simply due to measurement errors, peculiar to the infantile stage in which the subjects were supposed to be normal in their hearing, were presumably included. Conceivably this is one of the reasons why the hearing abnormality percentage of 3 to 4-year-old infants was relatively higher.