The aim of this study is to determine which of the many Eustachian tube function tests (or combination of tests) is most helpful in finding out what is causing ear problems in children and adult patients with middle-ear diseases thought to be due to poor Eustachian tube function. The Eustachian tube is a biological tube that connects the middle ear to the back of the nose and throat. When the Eustachian tube works normally, it opens and closes to help keep the pressure in the middle ear the same as room air-pressure (atmospheric pressure). When the Eustachian tube does not work well, the pressure in the middle ear can increase or decrease and feel like a blocked ear or cause ear pain. Poor Eustachian tube function can be associated with distressing middle-ear symptoms, predispose to middle-ear problems under conditions of rapidly changing air pressures such as occur during airflight and diving, and cause certain middle-ear diseases such as otitis media with effusion. It is also known that the results for the most commonly used Eustachian tube function tests in adults and children with various middle-ear diseases are poorer when compared to children and adults without middle-ear diseases. However, knowing that there is a difference in test results between groups with and without disease does not mean that any of those tests provide information useful in the management of individual patients with diseases due to Eustachian tube function. To be useful clinically, a test(s) that can accurately identify patients with a level of poor Eustachian tube function sufficient to cause middle-ear symptoms and signs and/or cause middle-ear disease is needed. To be very useful, tests should be able to diagnose the cause of any observed Eustachian tube problem so that treatment for that problem could be begun. The investigators would also want tests that could predict whether or not the ear disease will resolve with (or without) treatment and whether or not certain surgical procedures for middle-ear problems will be successful. Here, a number of Eustachian tube function tests are being used to diagnose and characterize the cause of Eustachian tube dysfunction in children and adults presenting to the research clinic with suspected poor Eustachian tube function and/or a recent history of middle-ear disease that can be caused by poor Eustachian tube function. After the testing, medical records will be periodically reviewed for 2 years and study participants will be contacted by phone to obtain information on their middle-ear disease, the response of the disease to any treatments and the success/failure of any surgical procedures used to fix middle-ear problems.