Do the same thing with a metal spoon. The metal made a higer pich than the wood wall. I also tried it with wire and it sounded much higher than with the string. When I used a spoon, I hit it real hard and it did a loud, vibrating bing. Now try experimenting.
Different materials vibrate differently.
See if you can hear a difference in the way a muffin tin sounds. Make a prediction. Be sure to tell us what you thought was going to happen and what actually did happen. When you're done, send your reports to our special feedback area. Every week we'll post new results from ZOOMers' Stereo Hanger experiments.