My son is nine, and he is also always talking/humming.. At 4, he had quiet time between 1 and 2 when his brother was napping. I don't remember how we convinced him to stay quiet - maybe used a chart.. Now, our saving grace is a drum set! Whenever he is fidgety he will either play/fight with his brother :), or play his drums. We have pads to make them quieter.. Maybe a piano (keyboard with volume control) or acoustic guitar would work, too..