Google Play also pairs with set-top box devices like Roku using an audio mechanism, although I'm not sure if it's ultrasound. A series of audible clicks are pre

Google Play also pairs with set-top box devices like Roku using an audio mechanism, although I'm not sure if it's ultrasound. A series of audible clicks are present while pairing, so I'm assuming it may be a different audio or environmental-based encoding, maybe even just location -> audio correlation rather than data modulated over any kind of over-the-air carrier. Does anyone know more about how that particular setup works? It sounds similar to the Shopkick app in a lot of ways.