We cut the balloon so we could fit it easily over the wide end of the funnel.
We fastened the rubber band to help hold it into place. We took our time patting the balloon while it was lose and then stretched tighter. The sound would change from high to low. Elijah decided that it was very much like our vocal cords. ;) Gotta love experiments.
As he played around with it we found it was acting like an eardrum when we spoke close to the balloon or through the funnel. The sound waves would cause it to vibrate just like the eardrum.
Very fun and easy experiment.
We were reading about sounds that bounce back like echoes and ultrasound. Elijah thought it was very fitting we were learning this after I had just had a sonogram. ;)
With Remy's help he observed how the potential energy was converted to moving energy and how it bounced back and forth after released.