szczys writes: One thing the human brain still does a lot better than computers is to recognize patterns within noise. That's why CAPTCHA uses distorted images to prove you're human, and random number generators are often inspected by visual representation. There is a technology that leverages this human knack for signal processing to make us part of the machine. The Hellschreiber is a communications device which has no idea whatsoever what the message actually is. It transfers a signal from one unit to the next, before being assembled into an image. A human looking at the image will see words, much like CAPTCHA. But even if the signal isn't perfect, our brains can often pick out the order within the madness, much like inspecting a PRNG for uniform distribution.