[Kat's Mom]

I like to bring in a big kettle, cover the top tightly w/ aluminum foil and sprinkle salt on it. We then use different items, ie., banging a pot lid with a spoon, a volunteer screamer, a whistle, etc., and I have the children make that noise close to the salt to watch it "dance". This is an excellent visual to prove to them that sound waves may not be visible, but they are moving nonetheless.