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


OBJECTIVE
To record changes in ME pressure over a period of time in normal human ears, while the ET is kept closed.


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.
Pau
Hans Wilhelm
HW
ENT Department, Medical School, University of Rostock, Doberaner Strasse 137-9, Rostock, Germany. hans-wilhelm.pau@med.uni-rostock.de
Sievert
Uwe
U
Just
Tino
T
Sadé
Jacob
J
D000158:Acoustic Impedance Tests; D000399:Air Pressure; D002199:Capillary Permeability / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism; D003196:Computer Graphics; D003679:Deglutition / Q000502:physiology; D004058:Diffusion; D004432:Ear, Middle / Q000098:blood supply / Q000502:physiology*; D005064:Eustachian Tube / Q000098:blood supply / Q000502:physiology*; D006801:Humans; D009092:Mucous Membrane / Q000098:blood supply / Q000502:physiology; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors
D002245:Carbon Dioxide