Here's an actual conversation I had with my fourth child at age 5, while reading an excerpt from "Little House in the Big Woods" by Laura Ingalls Wilder:
"...they hung the hog in a tree, took out the insides and left it hanging to cool. When it was cool they took it down and cut it up. There were hams and shoulders, side meat and spare ribs and belly. There was the heart and the liver and the tongue," I read. "So they ate every part of the pig back then--even the heart and liver and tongue!"
My son looked thoughtful. "Why do we have a tongue?"
"Why do you think we have a tongue?" I responded.
"Yeah! "What else do you use your tongue for?"
There were a few moments of silence. He furrowed his brow. "To talk?"
"Can you feel your tongue move when you talk? Try it!"
"La la la I'm talk-ing, I'm talk-ing!" We chanted exaggeratedly. We laughed. "Did you feel your tongue move?" He nodded emphatically.
"But your voice doesn't come out of your tongue, does it?" He asked.
"Where do you feel your voice coming from?" I smiled, excited about our conversation.
"What makes you think it's coming from your throat?"
He shrugged his shoulders.
"Touch your throat right here and hum. Hmmmmmmmm." He touched his throat and hummed and his eyes lit up. "That's where the sound is made!"
We then looked up a YouTube video showing someone's vocal folds while singing.