Why is it water only enters the ear sometimes?

[physics2]

Say your in a pool and u put your whole body beneath it, why is it that the water won't always enter your ear?

 

[Phrak]

ear wax?

 

[Nick666]

ear wax ?

 

[pallidin]

Prior to dissension, the "open" part of the ears(the outer ear canal in this case) contain atmospheric gases.

In order for water to enter, the gases must exit.

If you descend "left ear down", the gas pressure will prevent water coming into your left ear(to a certain point), but your right ear(pointing upwards) will easily release it's gases and flood with water.

As different humans have different ear canal structures, and we descend in water in different ways, what happens to one person is not the same for another.