PPL student here. I recently had someone ask over the radio if there was any traffic in the pattern (uncontrolled class G airport). I could make out everything that pilot said except for his radio call sign. (I'm still struggling a bit with understanding certain transmissions due to the "radio effect" and other interferences).
What is the appropriate thing to do when you want to respond to a transmission but couldn't make out the sender's radio call sign?
In this particular case I responded anyway, without addressing them explicitly, which didn't feel 100% "by the book". I later thought leading my response with "Calling aircraft..." might have been appropriate, but I'm not sure.