Haven't seen/heard one in years. Recall in a prior state we used to live that one would circulate around the neighborhood. Always had the impression the loud music was an attempt to create attention and let you know they were around. Seems to me if they run out of ice cream they would go back to the warehouse and refill............LOL. Wouldn't make any sense to drive around an empty truck that has nothing left to sell. A silent ice cream truck wouldn't be noticed by as many people.