Eustachian Tube Function and Default State

Normal Physiologic State

• The Eustachian tube opens transiently during swallowing or yawning to replace air that is naturally absorbed by the middle ear lining, maintaining pressure equilibrium between the middle ear and external environment, as supported by the American Academy of Otolaryngology-Head and Neck Surgery 1, 2, 3
• The tube must "seal off" the middle ear from germs and mucus in the nasopharynx, which requires a closed default state, according to the American Academy of Otolaryngology-Head and Neck Surgery 1, 2

Clinical Evidence of Closed Default State

• The Eustachian tube is normally closed at rest and opens only briefly during swallowing or yawning, as stated by the American Academy of Otolaryngology-Head and Neck Surgery 1, 2