Doppel creates a rhythmic pulse that you feel on the inside of your wrist as a heartbeat like vibration. We do not simply perceive this rhythm, but we entrain to it - a faster rhythm makes us feel more alert, and a slower one calms us down. The effect is similar to listening to upbeat or slower music. But with doppel, there’s no noise and no distraction. Filmed at the IDTechEx Show!