I recall from HPL that the tubes to equal pressure between ambient and the inner ear are called Eustachian (not sure of the spelling) Tubes. I think they run between the inner ear and the sides of your nose/throat . If you are subject to regular pressure changes as we all are to varying degrees then these tubes become wider and that allows us to clear them easier. I stand to be corrected, of course, but I'm pretty sure that's how it works. ........................Tailwinds
