What is That Sound?

On a dark, rainy, early morning we were traveling through St. Louis, Missouri, to sing at a grade school on the other side of town.  As always, we were traveling on unfamiliar roads when we heard a ticking sound rather like an egg timer.  The sound continued with Dave driving and checking the truck lights and the dashboard, while I tried to get a clear listen to where the sound was located.  Our surprise and relief was hilarious when we discovered the now impassioned ticking of our "Catch Phrase" game under papers and muffled by a travel pillow.  Dave had accidentally activated the game with his elbow.  We did not win that round.