Using the control data from parallel studies, the control subjects in this protocol and the subjects' history with respect to ME complaints, the evaluations of ETF, the feedback from subjects and the review of medical records, the investigators expect to develop an algorithm that prescribes the specific test sequences that optimize the diagnosis of the type and cause of ETD and the treatment recommendations for a given patient presenting with a specific history and set of ETD signs and/or symptoms. The investigators also expect to establish, with reasonable certainty, whether or not the results of these tests are clinically useful to otolaryngologists and general practitioners in their decision-making with respect to prescribed treatments and/or surgical interventions for affected patients. For each test or panel of tests, the investigators will define their sensitivity, specificity and accuracy with respect to the various outcomes.