29. Sonograph

After many years of experimenting with cymatics (see older posts) I came across another way of visualizing sound with vibrating membrane. This time I stretched a rubber membrane across the speaker and then attached a small piece of mirror in the middle where movement of the membrane is the most intensive. As a medium I used a laser beam focused directly on the mirror and reflected further on the screen. When speaker starts to move the membrane and the mirror, laser beam, following the sound with mathematical precision, draws dynamic lissajous figures on the screen.
And here's where's physics ends and creative process starts....