Have you ever closed the lid on an air-tight container containing a left-over hot meal and stuck it in the refrigerator? And than when you try to open the lid the next day once that hot meal cools down, it is REALLY hard to open the lid because of the accumulated negative pressure? In essence, the negative pressure has "locked" the lid down. Well, something similar can also potentially happen inside the ear with eustachian tube dysfunction , especially with negative pressure (rather…
