The orison seems to be an evolution of the cell phone. (
Cloud Atlas came out in 2003, when cell phones were common but before the widespread popularity of smartphones.) The word “orison” means “prayer,” suggesting that in the future, people will replace religion with a worship of technology, for better or for worse. In Sonmi’s world, brand names become generic terms, with films becoming “disneys” after the massive entertainment company Disney, and so it’s possible that “orison” is a corruption of “Verizon,” one of the biggest cell phone companies in the real world at the time.