ETF will be evaluated in this highly heterogeneous population using a pressure-chamber protocol (ET stress test), a panel of other tests as is relevant to the status of the tympanic membrane and, in older subjects (10 years and older, or younger if tolerated), endoscopic assessments of nasopharyngeal pathologies. The goal of this study is to define the least costly panel of test procedures that is sensitive, specific and accurate for the diagnosis of ETD, identification of the cause of the dysfunction if observed, prediction of the success rates for medical or surgical interventions (e.g. the newer ET surgical procedures, adenoidectomy, myringoplasty) and prediction of future disease course (probability of spontaneous resolution). These results will be interpreted in terms of whether or not ETF testing is of practical value to clinicians in their decision-making related to ETD, otitis media with effusion (OME) and chronic OME (COME) and if relatively portable, inexpensive test systems with the listed properties can be introduced into a typical physician's practice.