This is not formally done in front of an audience. It's a read-through, as JMurray said.
A radio play is performed in a studio.
A dramalogue appears in only one dictionary in the OneLook site. Where did you encounter this word?
Rover! I don't know how to thank you, you made me certain and MORE THAN IT, the OneLook site taught me a new way for research. From now on I want to teach it in some of my classes so it would be good for research-students too.
By the way, a read-through is sometimes played in front of audience when the time is limited and the university students want to play more scripts, or when the students don't have enough time to make a complete play but they don't want to miss the chance to show their attempt,...
I don't remember exactly but I think I got the word 'dramalogue' from the terms students used during my education. I didn't study the Arts, so it's only a shadow.