Except… the world sounds like you’re underwater. Your own voice sounds muffled and distant. And that dull, achy pressure in your ears? It feels like a tiny, angry gnome has taken up residence in your eustachian tubes.

But if you have a cold, allergies, or just narrow tubes, the pressure gets trapped. Your eardrum stretches inward or outward like a drum skin being pulled too tight. Result? Muffled hearing, a “full” feeling, and sometimes pain.

Your hearing will return. The gnome will leave. And next time you fly, you’ll be the calm person handing gum to the panicking passenger next to you.

But don’t panic. Here’s why it happens, and—more importantly—how to fix it. Let’s get the quick science out of the way. Your ears have a pressure-regulation system (the eustachian tubes). During takeoff and landing, cabin air pressure changes faster than your body can keep up. Normally, swallowing or yawning opens those tubes and equalizes things.