Since that time there's been a few efforts to revive radio as the "theater of the mind" but with little success. (Even the Star Trek actors Patrick Stewart, John DeLancie and Leonard Nimoy were unable to generate much interest with their series of adaptions of radio science fiction greats.)
In England, on the other hand, radio is as popular now as ever and its official "TV guide" is actually called The Radio Times and gives both TV and radio info.
And lots of British actors love supplementing their income by appearing on radio, or just love appearing on radio altogether. You can listen to classic radio comedy and drama series by going to http://www.bbc.co.uk/radio4extra/programmes/schedules.
The radio comedy series Cabin Pressure, written by John Fennimore and starring Fennimore as Artur, Roger Allam as Douglas, Stephanie Cole as Caroline Napp-Shappey and Benedict Cumberbatch as Martin Crief, made its debut with 6 episodes in 2008, another 6 in 2009, another 6 in 2011, and the final 6 in 2013, with a 2 part show finale airing over Christmas in 2014.
Radio certainly doesn't pay as much as TV work and not nearly as much as film work, so I do wonder if Cumberbatch (and the others) accepted 'union minimum') because they love working on radio.
Purchase the entire series (and help support this site, as I'm an Amazon affiliate and get a percentage of the sale) and show the Brits that Americans love British radio:
Here are a few publicity photos done by the BBC for Cabin Pressure
Captain Martin Crieff shows First Officer Douglas Richardson how many rings he has on his sleeve
The crew of Cabin Pressure. The guy giving the V for Victory sign is John Fennemore, the creator and writer of the series
Cabin Pressure was recorded live before a studio audience - so that laugh track you hear on each episode is real laughter. There are many fans of Cabin Pressure out there. Do a Google search on "Cabin Pressure Cumberbatch" for images, and you'll find talented artists have created illustrations for all the characters. In addition, although I don't think cameras were allowed at the recordings (and sadly, neither were video recorders) people did take photos and share them on the web.
Benedict Cumberbatch laughing at something funny in the script of Cabin Pressure
Behind the scenes. All the actors cluster around the same microphone and read from scripts
Has to be an extremely sensitive microphone!
In the "Wokingham" episode, big brother Simon teaches Martin how to fly
The actors enjoying themselves