If during conversation, I face problem in understanding what the other speaker is saying, I may come with following polite statements:
"Sorry...?"
"Sorry, could not get you..."
"Pardon me..."
"Come again please..."
But my inability to understand can be due to two reasons. 1) "I could not hear what you said" and 2) "I could not understand what you said."
But as far as I know, the aforementioned statements can't help differentiating between the situations. So my question is Is there any polite expression out there which can explicitly tell for what reason I could not understand you?
If such expression/phrase exists, the speaker can understand the reason and take necessary step accordingly i.e. either elevate his voice or rephrase what he is saying.