This is intended for use in a haunted house or at a Halloween party. Just hit the green flag and it does the rest. Make sure you allow Scratch access to your microphone. It is recommended to hide the computer monitor in the wall (there are great tutorials for this on YouTube.) This one was designed to be used with a picture frame to make a haunted painting, hence the backdrop, but you can use it however you see fit. Because it is noise-activated, I would recommend that you display it in a quiet setting so that it is not accidentally activated. For your convenience, it is on a twenty-second timer so it does not constantly activate.
I have seen this idea in various places. I did not copy any specific tutorial. The backdrop is from this address: https://www.google.com/imgres?imgurl=https%3A%2F%2Fimg00.deviantart.net%2Fe3c3%2Fi%2F2014%2F282%2F3%2F0%2Foil_painting_background_by_billijoearm_d7jtpwv_by_insan404-d828r5n.jpg&imgrefurl=https%3A%2F%2Finsan404.deviantart.com%2Fart%2FOil-Painting-Background-By-Billijoearm-d7jtpwv-487497083&docid=zg7DKiIHDckj6M&tbnid=yCaqflZsndSo4M%3A&vet=1&w=1024&h=768&bih=637&biw=1366&ved=0ahUKEwj3pd_p6b_aAhUGWa0KHXHlAFQQMwiKAigNMA0&iact=c&ictx=1
