Whoo, whoo! says the old-fashioned steam engine when all nine puzzle pieces are placed on top of the puzzle board's matching picture. Light-activated sensors trigger high-quality recorded sounds from the built-in speakers. Children will "get on board" with matching and listening skills while playing with this attractive wooden puzzle from Melissa & Doug. This sound puzzle encourages problem-solving skills and independent play. For children ages 3 years and above. Two (2) AAA batteries required (not included).