Eustachian tube

The passage that runs from the middle ear into the back of the nose, just above the soft palate. The tube acts as a drainage channel from the middle ear and maintains hearing by opening periodically to regulate air pressure. The lower end of the tube opens during swallowing and yawning, allowing air to flow up to the middle ear, equalizing the air pressure on both sides of the eardrum. When a viral infection such as a cold causes blockage of the eustachian tube, equalization cannot occur, resulting in severe pain and temporary impairment of hearing. A person with a blocked eustachian tube who is subjected to rapid pressure changes may suffer from barotrauma. Glue ear or chronic otitis media may occur if the tube is blocked, preventing adequate drainage from the middle ear. These conditions, which often result in partial hearing loss are more common in children. This is partly because their adenoids are larger and more likely to cause a blockage if they become infected and partly because children’s eustachhian tubes are shorter than those of adults.