Enunciation in old radio shows

A goodly percentage of the general population does not enunciate clearly while speaking. We are so accustomed to it that our brain translates the speech pattern and we get the general gist of the conversation despite that fact. However, on old radio shows, we did not have the advantage of reading lips, plus there was some loss of clarity due to transmission over the airwaves, all of which would have been AM in those days. So, the actors had to enunciate very clearly, even though the characters they were portraying might have been far from doing that in real life.