Patulous Eustachian tube (PET) is the name of a physical disorder where the Eustachian tube, which is normally closed, instead stays intermittently open. When this occurs, the person experiences autophony, the hearing of self-generated sounds. These sounds, such as one's own breathing, voice, and heartbeat, vibrate directly onto the ear drum and can create a "bucket on the head" effect. PET is a form of eustachian tube dysfunction (ETD), which is said to be present in about 1 percent of the general population. Signs and symptoms With patulous Eustachian tube, variations in upper airway pressure associated with respiration are transmitted to the middle ear through the Eustachian tube. This causes an unpleasant fullness feeling in the middle ear and alters the auditory perception. Complaints seem to include muffled hearing and autophony. In addition, patulous Eustachian tube generally feels dry with no clogged feeling or sinus pressure. Patients hear their own voice or its echo from inside. They describe it as being amplified and unpleasant. Lying head down may help since it increases venous blood pressure and congestion of the mucosa. Causes Patulous Eustachian tube is a physical disorder. The exact causes may vary depending on the person. Weight loss is a commonly cited cause of the disorder due to the nature of the Eustachian tube itself and is associated with approximately one-third of reported cases. Fatty tissues hold the tube closed most of the time in healthy individuals. When circumstances cause overall body fat to diminish, the tissue surrounding the Eustachian tube shrinks and this function is disrupted. Activities and substances which dehydrate the body have the same effect and are also possible causes of patulous Eustachian tube. Examples are stimulants (including caffeine) and exercise. Exercise may have a more short-term effect than caffeine or weight loss in this regard. Pregnancy can also be a cause of patulous Eustachian tube due to the effects of pregnancy hormones on surface tension and mucus in the respiratory system. Granulomatosis with polyangiitis can also be a cause of this disorder. It is yet unknown why. PET can occur as a result of liquid residue in the Eustachian tube, after suffering a middle ear infection (otitis media). Radiation therapy High levels of estrogen Nasal decongestants Stress Sudden weight loss Neurological disorders Diagnosis Upon examination of a suspected case of patulous Eustachian tube, a doctor can directly view the tympanic membrane with a light and