Your ears sometimes pop in airplanes, while driving through high mountainous areas, and at other high altitudes because of air pressure changes. As you ascend in an airplane, for example, and the air pressure decreases, the air trapped in your inner ear will cause your eardrums to push outward. This expansion causes the discomfort you feel before your ears “pop.” Your hearing ability also decreases because the pressure on your ear drums makes the sound harder to transmit. When you yawn or swallow, your body can equalize the pressure between your inner ear and the atmosphere by allowing some air from your inner ear to escape through the Eustachian tubes, two small channels that connect the inner ears to the throat. When they open, you feel the pressure release and you hear a popping sound.