This device produces figures from sound vibrations. When you sing into the microphone, the vibration of your voice is transmitted to the membrane of the speaker, and to the mirror attached to it. As it oscillates, the mirror reflects the laser point, turning it into a line. The line becomes a figure when reflected by the second mirror. If you two sing notes, the figure will be a curve. Consonant notes produce circles, infinity symbols, and other simple figures. The more dissonant the notes, the more complex the figures. Notice how the sounds your ears perceive as harmonious produce figures your eyes perceive as harmonious.