Why can't I hear when making a call?

[AC Question]

why cant i hear when making a call

I just got my screen replaced it was working fine but now when o get a call or make a call I can't hear the ringing before the call is connected n I can't hear when I pick up a call m the other person say they hear a humming sound. Could that mean that the speaker wire is lose or got unconnected from when they replaced my screen?