Audiometry and tympanometry in relation to middle ear effusions in children

Abstract In a group of 84 children with concurrent or recent middle ear disease, tympanometry and air‐conduction audiometry were compared in their ability to predict whether or not middle ear effusion was present. In addition, in children with effusions, correlations were sought between audiometric and tympanometric measurements, and the viscosity of liquids found at myringotomy. The clinical descriptions of effusions matched, in general, measurements of their viscosity. Effusions were found at myringotomy almost as often in ears with average air‐conduction thresholds below 25 db as in those with higher thresholds; in both groups an appreciable proportion of the effusions was of high viscosity. Tympanometric patterns, representing tympanic membrane compliance and middle ear air pressure, were of five general types. Effusions were found at myringotomy in most of the ears with low tympanic membrane compliance, but were not found when both tympanic membrane compliance and middle ear air pressure were normal. Sixteen ears with average air‐conduction thresholds below 25 db, but found to contain effusions at myringotomy, also had received pre‐operative tympanometry: in each instance tympanic membrane compliance had been abnormally low. The existence of negative middle ear air pressure suggests the possibility of Eustachian tubal obstruction, but the definition and conditions of abnormal levels in children remain to be established. Children with high negative middle ear air pressure should probably be considered at otologic risk. Tympanometry appears to be a reliable method for detecting the presence of middle ear effusion in children, and, therefore, should prove valuable for screening.