Keep your ears from popping..

McNally was taking his first plane ride, flying over the Rocky Mountains. The stewardess handed him a piece of chewing gum. “It’s to keep your ears from popping at high altitudes,” she explains.
When the plane landed McNally rushed up to her.
“Miss,” he said, “I’m meeting me wife right away. How do I get the gum out of me ears?”

How old?

Unusually deep