CONTINUOUS LONG-TERM MEASUREMENTS OF THE MIDDLE-EAR PRESSURE IN SUBJECTS WITHOUT A HISTORY OF EAR DISEASE

A new method was used for continuous measurement of the middle ear (ME ) pressure during a 24-h period. In 10 subjects without a history of e ar disease a small perforation was made through the tympanic membrane. A tight rubber stopper containing a small polyethylene tube was fitte d into the external ear canal. Conventional tubal function tests were performed. The equipment was then carried by the subjects for 24 h of normal activity to monitor any slow or rapid dynamic pressure change i n the ME. Body position was found to be the most important factor affe cting ME pressure variation, during the 24-h continuous pressure measu rements. A significant pressure rise occurred in the recumbent positio n in all but one subject. Few rapid pressure equilibrations were seen during the recordings, indicating few tubal openings. This implies tha t the pressure changes in the ME seen in this study were mainly the re sult of gas exchange over the mucosa. The investigation might be a bas e for reference when investigating different kinds of pathologic condi tions in the ear.