Verbalization is the act of saying something out loud. An extremely formal new dad might talk excitedly about his son's first verbalization.
Use the noun verbalization to describe the spoken expression of a thought or idea in words. It's a fairly formal way to talk about talking, and you're most likely to come across it in a textbook or a college class. You might read about the fact that parents' verbalization has a big influence on their children's vocabularies. Verbalization stems from the verb verbalize, which now means "say out loud," but originally meant "use too many words."