The Millennials lead other age groups in media consumption on smartphones but watch the least amount of live television, per Nielsen. A new audience report from the media firm says adults between the ages of 18 to 34 watched about 22 hours of TV a week. Adults off all ages spend 36 hours, on average, watching TV. The Millennial set spends "nearly as much time using digital devices as a whole as they do watching TV," the study said. Radio remains the most widely used device, with 93% of adults saying they listen to it each week.