Why do your ears sometimes pop when you drive down a steep incline or descend in an airplane?

???

It's the change in air pressure with altitude, air pressure decreases the higher you go and increases when you go lower, the body has a tube connected from the inner ear to the throat to clear pressure from the inside to equalize with the outside (this works perfectly when say hiking up a hill but when the rate of pressure change is faster than a certain rate it does not keep up very well causing an imbalance in the pressure in the inner ear (behind the ear drum) and the outer ear (outside the ear drum) as such the ear drum becomes compressed in one direction or the other, when the pressure is equalized the ear drum springs back into its normal shape and in doing so the movement produces a movement of air these are detected by the receptors in the ear that allow you to hear as a pop sound and thus why your ears pop.

It is also for exactly this reason why your ears can sometime hurt and you need to actively alleviate the pressure yourself to help it equalize, in this case the pressure difference has become quite large and as such the ear drum is becoming stretched too far, this activates stretch receptors that tell your brain the ear drum is under too much strain with a pain signal (the same as what happens when you are exposed to a noise which is too loud, as sound is a compression wave it pushes the ear drum too much and causes pain).

change in elevation and air pressure.....

its because of the change in presure. o and did u know, when your flying, your basicaly just gliding through air!

Pressure

Because your lucky.

The change in air pressure. The same thing happens when you dive.