Digital-media use to average 15.5 hours a day by 2015, study predicts

Americans are spending more time on their digital devices, and that won't change for years, according to a new study.

The University of Southern California report shows that Americans consume "an enormous amount" of media via television, radio, phone and computer, amounting to an average of 63 gigabytes per person per day in 2012. All told, total US media consumption reached 1.46 trillion hours in 2012, an average of 13.6 hours per person per day, a year-over-year increase of 5%. Those numbers are expected to increase in the coming years. By 2015, data indicate that Americans will consume media for more than 1.7 trillion hours, an average of 15.5 hours per person per day. Mobile messaging hours, which in 2012 accounted for about 9% of voice call hours, will double to more than 18% of voice hours, a year-over-year growth rate of more than 27%, the report said.