Evacuation of the middle ear by sniffing: a cause of high negative pressure and development of middle ear disease.

Previous research on eustachian tube function has been devoted mainly to the study of the tubal opening ability and pressure equalization. This article summarizes a series of experimental studies focusing on the closing ability of the tube. Results support the belief that the purpose of the tube should be seen primarily as protecting the middle ear from the extensive pressure variations that physiologically take place in the nasopharynx. A number of studies of diseased ears have shown that tubal malfunction was characterized mainly by a reduced ability to withstand negative pressure in the nasopharynx. Sniffing can evacuate the middle ear, causing high negative intratympanic pressure. It seems likely that this mechanism is involved in the development of middle ear effusion and manifest retraction-type middle ear disease.