A blockage of the Eustachian tubes between the middle ear and the pharynx: Otic barotrauma is a result of rapidly changing external air pressure, such as that which occurs during descent of an aircraft. This can cause ear pain, ringing, occasional dizziness, and diminished hearing.

"Eustachian tubes" are the passages, one on each side of the throat, which lead to the middle ear. The tubes open widely in the act of swallowing or yawning.

The opening into the throat is situated just behind the lower part of the nose, so that a catheter can be passed through the corresponding nostril into the tube for inflation of the middle ear.

"Valsalva's Manoeuvre", the pinching of the nose with the finger and thumb and attempting to blow hard through the nose, will usually relieve the blockage.