Sound is not only for hearing but also a fascinating physical phenomenon that can be seen. A standing wave is formed by the superposition and interference of two sound waves with the same frequency moving in opposite directions. At specific frequencies, certain points in the medium remain stationary (nodes) while others vibrate with maximum amplitude (antinodes), creating a stationary "wave pattern." Our interactive exhibit, "Sound Standing Waves," makes this invisible force vividly visible. The exhibit consists of a transparent tube, lightweight internal particles, a speaker, and a frequency adjustment knob. By rotating the knob, participants control the frequency of the sound emitted by the speaker. As the frequency changes, they witness firsthand how the particles are precisely manipulated by the invisible sound waves: dancing vigorously at the antinodes while remaining mysteriously still at the nodes, clearly outlining the "shape" and path of the sound.WhatsAPP?+86 18882709667