First we read these books:
Loud, Soft, High, and Low Sound by:Natalie Rosinsky
All About Sound by Lisa Trumbauer
What's that sound? by Mary Lawrence
We practiced bending our ruler and letting it make vibration sounds.
We colored a picture of a rabbit and then I rolled it up and we seen how having big rabbit ears allowed us to hear better.
We felt our vocal cords vibrate as we talked!
I had him feel the vibration on his triangle when he beat against it.
Then I lined up 3 glasses of varying amounts of water. I had him listen to them and tell me which was a higher pitch sound, which made a lower pitch sound, and which one vibrated the most.
Then I gave him a spoon and a fork. I had him bang the spoon and fork together and listen to the vibrations of the forks tines. Then I put a cotton ball on the end of the fork and had him bang together again. No sound!