Want to do what all the cool kids do? Talk to your smartphone, apparently. Google has commissioned a study showing that American teens are considerably more likely to use voice search on their devices than adults. About 55 percent of the 18-and-under crowd uses Cortana, Google Voice Search or Siri more than once a day, while 41 percent of grownups do the same. That number climbs to an even higher 75 percent for teens glued to their phones 11-plus hours a day. Younger users aren't worried about social stigmas, either -- they're far more likely to use voice commands when friends are around (57 percent versus 24 percent). About 45 percent of adults, meanwhile, are self-conscious about their geekiness when they speak to their devices.