Pressure changes in the human middle ear without opening the eustachian tube.

Conclusion: By means of a direct, though non-invasive experiment on healthy humans we could demonstrate that middle ear (ME) pressure decreases when the eustachian tube (ET) does not open. Thus with a very simple method the basic theory of continuous gas loss from the ME into the circulation and the replenishment of the loss through the ET could be validated.
Objectives: To record changes in ME pressure over a period of time in normal human ears, while the ET is kept closed.
Subjects and Methods: On-line tympanometry was carried out in three subjects, who refrained from swallowing for 20-120 min.
Results: During the time when the ET was kept closed by refraining from swallowing, tympanometric monotonous pressure decrease was recorded. Once the tested subject could not refrain from swallowing any longer and swallowed again, ME pressure equalized immediately.