The acoustic reflex in children without an hermetic seal

In clinical practice with children, the hermetic seal is either often not obtainable or is lost before acoustic reflex measures are obtained. In a recent study, Surr and Schuchman (Archives of Otolaryngology 102, 160--161, 1976.) found that in the majority of cases reflex thresholds could be measured in adults with normal middle ears in the absence of an hermetic seal. This study was designed to find out whether the conclusions of Surr and Schuchman could be extended to children. Sealed and unsealed reflexes were compared in 30 children, ages 3 to 7, with normal middle ears. Results indicated that: (1) approximately two-thirds of the children demonstrated reflexes in the unsealed condition; (2) differences between sealed and unsealed reflex thresholds were not clinically significant; (3) in most cases, unsealed reflexes were measurable at all frequencies or at none; (4) neither size of ear canal volume nor amplitude of the sealed reflex at 10 dB SL seemed to be related to the presence or absence of the unsealed reflex. It was concluded that reflex thresholds obtained in the absence of an hermetic seal may be considered valid but the absence of an unsealed reflex should not be considered diagnostically significant.