Learn and quiz

Learn the signals by feel.

Six signals and the drop-off signature carry the whole language. Learn them one card at a time. Then take ten quiz rounds and see how well you read them by sight, by sound, or by the phone in your hand.

Outputs

Turn these on to hear and feel each signal. Sound plays here in the browser. Phone buzz works on an Android phone. M switches sound from anywhere.

Sound needs a browser with Web Audio.On an Android phone this page can buzz too.

Every timing here comes from the research behind the kit. A steady buzz quickens from a 900 ms rhythm at the edge of range to 250 ms at contact. The sweep fires four ankle motors in 120 ms bursts 80 ms apart, one stroke every 800 ms. The drop-off is two 80 ms pulses every 600 ms. When you know them, walk the block in the simulator.