Abstract
The pressure in the eustachian tube was measured in 22 normal subjects by a pressure transducer with a diameter of 1 mm, The pressure was first recorded with the transducer advanced as much as possible, and then recordings were made at 5 mm intervals as it was withdrawn. The internal pressure at rest in the isthmus region was 19.5±20.1 mmHg, and decreased gradually toward the pharyngeal orifice of the eustachian tube. The variation of pressure on swallowing was the maximum at the region of 15 mm-20 mm from the pharyngeal orifice. The duration of movement of the eustachian tube on swallowing was approximately 900 msec. In the region of 15 mm-20 mm from ostium pharyngeum tubae auditivae, the eustachian tube became opened after approx. 300 msec from the beginning of the swallowing movement, remained open for about 300 msec and closed in about 300 msec. The wave-form of the internal pressure on swallowing differed with the regions in the eustachian tube.
