ASL AI vision detection, used to test users on their ASL knowledge in a monkeytype format Before starting, make sure you have a white background behind you with your face out of the camera to maximize visibility. First, you can choose between practicing letters and numbers. Next you can choose how much type you want to go, from 15s, 30s, 60s, or 120s. Then you can press start to begin to and sign the letters based on what’s shown. You must hold each character for 0.5 seconds.