For one of my projects I need to visualize a voice somehow. So I tried to recreate a Chladni plate out for not to much money. I took a wooden frame, tightly stretched a trash bag over it, and placed a blue-tooth speaker in a bucket beneath it. I used salt as the visualizer of the sound waves for the first test.
I used my brother's song as a sample. Notice how the salt skates not in a straight line, but in a strange winding pattern depending on the beat and pitch.
I'll need to make some adjustments, I have a few things to try out instead of sugar, but I'm happy with the first step.