Answer:
I don't want to spill the beans.... but
How to be an active listener in a formal setting?
One can be an active listener by paying close attention and asking relevant questions through politeness. That person could also take notes.
In an informal setting, such as when talking to a friend, nothing should distract you, and you shouldn't wave away anything that person has said lackadaisically.
Glad if it helped!
I didn't completely understand the question, but here