LeapFrog: The Letter Factory (2003)

With an idea to create a talking letter book, Dad has an important presentation for his boss, Mr. Websley! When the family joins him at the letter factory where he works, the decide to pitch in to help. Tad, the youngest sibling, leaves the group when he admits to not knowing the sounds that letters make. He soon finds Professor Quigley, who offers him a tour of the letter factory with stops in rooms dedicated to each letter of the alphabet. In each room, letters are being trained to make their appropriate sounds. By the time he reaches Z, Tad knows all his letter sounds, Dad's presentation is a success, and Mr. Websley's talking letter book is destined to be a top seller.