The Screechophone uses the “playing card in the spokes of a bicycle” effect to play certain frequencies. This particular device was built and destroyed in a mad rush so it no longer exists, but I think the lilting tones of the Blue Danube Waltz merged with the howling of the card as it spits its horrible noise into the ether is gentle enough to put the aged and babies to sleep yet still reminds us that people are crazy. There’s also some mention of a photosensor in here but I can’t tell where it sits between the CD player, the whirling disk, and the Commodore 64.

via Make