Setting the Tone: Tonoscopes in the ILab

Shore’s Innovation Lab, or ILab for short, is almost always abuzz with some sort of exciting project, demonstration, or independent student work. This is a special place where dreams and lofty ambitions become reality for students of all ages. In Grade 4’s tonoscopes project, students were encouraged to think outside the box as they embarked on an interdisciplinary lesson on the science of sound. They began their investigation in science class with Lower School Innovation Specialist Jill Codding, learning about wavelengths, amplitude, and frequency. Students then teamed up with Upper School Innovation Specialist Cam McNall in the ILab to explore cymatics, the study of visual sound and vibrations. Using PVC pipe, balloons, and rubber bands, the students built their own tonoscopes. 

First, students worked together to squeeze a balloon onto the end of a PVC pipe. The pipe had an elbow, which means it had a junction where a skinnier PVC pipe was attached at a forty-five degree angle. Students sprinkled salt on top of the end with the balloon on it until it was covered, and then made noise into the end of the elbow segment. This contraption is called a tonoscope. Students talked, hummed, yelled, and sang into the pipes at a variety of pitches and volumes and were fascinated by the results.

When noise entered the elbow end of the tonoscope, the salt on the balloon end would move with the sound, creating intricate and beautiful patterns which captivated the students. The higher the pitch of the noise that the students made, the more the salt moved. The louder the students were able to make noise, the more the salt jumped up and down on the balloon. “They experimented by singing different pitches at different volumes, and observed the complex patterns that were created on the balloon surface by the grains of salt. The students reflected on the patterns using their former knowledge about sound and sound waves. They had so much fun making sound visible with their own voices and hand-made tonoscopes!” said Music Teacher Alexandra Asacker, who helped organize the project. The entire process was a sight to see and captured the attention and wonder of the students. “The higher we went, the faster it moved around,” said Seb A. excitedly, “I feel like the people who can get their voices the highest can make the salt move super fast!” The class was engaged throughout the session and disappointed when they had to leave, insisting on a number of ‘last ones’ before moving on to their next class. 

The reason why the salt moves in such interesting ways comes down to the wavelength of the sound entering the pipe. High pitch sounds have higher frequency wavelengths, meaning that the waves are closer together and the salt is getting hit by more waves at a time than lower frequencies. Meanwhile, louder sounds carry a higher amplitude, causing the sound waves to become “larger” and more powerful, causing the salt to jump. This project is just one small piece out of a myriad of work which makes up the students’ vibrant ILab curriculum, and Shore is incredibly lucky to have such a dynamic and knowledgeable instructor in Cam McNall to watch over the space. McNall is adored by the students for his kind and patient demeanor, willingness to help, and dedication to his work.