G'day again,

JennieG: I seem to remember that the local airlines' used to hand out hard butterscotch (or similar) sweets for passengers to energetically suck - in order to "massage" the ear passages during changes of altitude.

I've picked up enough control of those muscles to be able to both 'block' and 'clear' my ears voluntarily ... and this is, aparently, also presented as a Yoga technique (but I don't know its name!).

Enjoy the trip

Bob