MORE RADIO AUDIENCE NUMBERS

I'm still looking to find hard data on the size of the listening audience for the radio gasbags and in this article, I found another clue.

A Quest to Save AM Before It’s Lost in the Static

By EDWARD WYATT
Published: September 8, 2013
NY Times

In 1978, when Mr. Pai was 5, half of all radio listening was on the AM dial. By 2011 AM listenership had fallen to 15 percent, or an average of 3.1 million people, according to a survey by Veronis Suhler Stevenson, a private investment firm. While the number of FM listeners has declined, too, they still averaged 18 million in 2011. (The figures are averages based on measuring listeners every 15 minutes.)