A startup named SonicNotify embeds inaudibly high-pitched audio signals within music or any other audio track. When a compatible app hears that signal, it triggers any available smartphone function to hyperlink you to websites, display text, bring up map areas, display a photo, let you vote on which song a performer plays next and so on.
Lady Gaga could have utilised its technologies on her Monster Ball tour1, and Coachella 2013 and other events are subsequent in line. To interact by way of SonicNotify, fans can use any SonicNotify-enabled app.
“With Sonic, we can unlock something that your iPhone or Android can do, as extended as the SonicNotify SDK is built into an app that’s operating in the background on your telephone,” explained SonicNotify. “For example, some of the stuff we’re performing with Gaga is when she is performing, mid-set, absolutely everyone in the arena gets a notification which lets them decide on which song she plays for her encore.”
Why Lady Gaga Could Deploy a Sound Only Your Smartphone Can Hear [Wired]