Today we learned about sound and made some noise! Sound is created when something vibrates, for example our vocal cords. The vibrations travel through the air as sound waves. When the sound waves reach our ear they vibrate the eardrum, and we hear a sound. We used rubber bands to make sound. We observed how the rubber bands vibrate as they produced sound. The sound pitch depends on the thickness of the rubber band, thin rubber bands have higher pitch.
Next, each girl made a kazoo. Kazoo is a fun noise making instrument, and is super easy to make: simply attach a small piece of wax paper to one end of a paper roll with a rubber band. When the girls talked into the kazoo, the wax paper vibrated creating a funny sound. They could feel the vibration by gently touching the wax paper while speaking.
Another experiment to demonstrate sound waves proved to be a bit tricky for the girls. For this experiment, sprinkles are placed on a plastic wrap, which is tightly stretched above a small bowl. The goal is to make the sprinkles bounce by talking directly above the plastic wrap. It didn't work that well but was fun, and girls ended up eating the sprinkles instead...
Finally, we explored how sound waves travel with old fashioned telephones. As a kid I loved to use these simple phones, which are made by connecting two plastic cups with a long string. When the string is tight sound waves can travel through it. The girls enjoyed using the phones to talk with each other, and it was a great demonstration for the three parts of sound: a vibration source, a medium for the sound waves to travel through, and a sound detector.