 pressurizing or depressurizing the cabin the only other possibility could be you know air conditioned air tends to be low humidity could that have led to a pretty quick um you know closing off of the eustachian tube which gave you a little negative pressure maybe but that's a slower process i would think if it was pretty immediate it was probably an air pressure differential you were experiencing and it lasted about an hour until i got home and got a tractor and i was fine