T.B.
Hi ET!
Reading your question made me remember a funny story. My daughter was just a little younger than your little man when she decided that she was going to be loud all the time. Not a moment went by that the neighbors did not know when she was awake. So one day a friend had come to visit and she was in her playpen while I was cleaning up a bit. He was picking at her and trying to find something for her to watch on tv. So with remote in hand he said to me "I wonder if this works..." and he pointed the remote at her and pushed the down button for the volume. Amazingly enough, her volume went down. It was the funniest thing. It only worked once though...darnit! :-)
Now on to advice...
When working in daycare I learned that if you would speak in normal tones or whispers to the children they have to be quiet to listen. My youngest daughter (now 3) will do it to me if I get to loud :).
I have always believed that if a child is being quiet they are up to something...so quiet= trouble and noise = playing.