The Eustachian tube pressure-balances the middle ear against altitude changes

Evidence

There is a narrow channel called the Eustachian tube connecting the middle ear to the oral cavity. The role of this tube is to balance the air pressure between the middle ear and the environment, for example during changes in altitude, such as in aeroplanes during takeoff or landing. Too high or too low a pressure in the middle ear displaces the eardrum and reduces the sensitivity of hearing, or may even cause pain. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 735

Categorization

• corroborated: 3 independent passages support this claim — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 735