Simple Science Experiments. Visualization of sound vibrations.

Friends! During this difficult period of the pandemic for all of us, we decided to experiment a little before going into quarantine. I now have a new friend and like-minded person. I hope that when the pandemic stops we will be able to please You with new experiments. So. In one of the videos, I used a generator on the NE555 to get different frequency sound vibrations , here is the link . I had the idea to visualize these vibrations, not on an oscilloscope, but on a simple scree