Grade 7 science students in Alex Randhava's classes are learning about sound waves and have been tasked with building an "ear" device that detects sound waves and distinguishes between high and low volumes. Since an ear can also distinguish between high and low pitches, the students' devices must do the same.

The prototypes students created focused on sensitive constructions that can transmit vibrations. One design incorporates a laser pointer held within tightly stretched rubber bands attached to a frame. The laser projects onto graph paper, making every tremor in the air visible in both size and speed. Students have observed that this device detects high-frequency sounds better than low-frequency sounds. They are constructing a second device with lower tension to see if it can reveal lower frequencies.

Another device resembles a tall pendulum, sensitive to vibrations and capable of recording them on paper as it oscillates. A third device uses water as the vibrating element, with a floating raft designed to record the waves. These innovative designs not only enhance students' understanding of sound waves but also encourage creativity and experimentation in science.