The median age of a broadcast or cable television viewer during the 2013-2014 TV season was 44.4 years old, a 6 percent increase in age from four years earlier. Audiences for the major broadcast network shows are much older and aging even faster, with a median age of 53.9 years old, up 7 percent from four years ago.

These television viewers are aging faster than the U.S. population, Nathanson points out. The median age in the U.S. was 37.2, according to the U.S. Census, a figure that increased 1.9 percent over a decade. So to put that in context of television viewing, he said TV audiences aged 5 percent faster than the average American.

The research shows a sharpening age divide in the entertainment industry that has traditional media scrambling and newcomers such as Vice and Netflix establishing their own online empires.