Call Audio not working?

Hello, so this morning my phone was fine. I just got off of the phone with a friend and the audio and display was fine. I think as I got out of the car I dropped my phone and that's when the problems started.

My phone works completely fine all around except for when I go to make a call or when someone calls me. When I make a call, the display locks up and there's no sound coming out of the earpiece or when I put it on speaker. After I'm finally able to get my phone to end the call, I tested my music and audio on other applications and it works just fine.

The only thing that fixes it temporarily is knocking on the side of the phone to get the sound back and the display unfrozen. I've tried restarting my phone three times, pressing my thumb down gently on the top speaker in case of a loose connection, and exiting out of everything on my phone. Even FaceTime works but as far as just audio it will not cooperate.

If somebody can please have any idea what's going on and explain it would be much appreciated!