Q: Caller can't hear me and I can't hear them speaker works Bluetooth is off

A Couple of days ago I had an incoming call.  I answered the call but could not hear the caller and they messaged me that they could not hear me either.  i attempted several calls to a person sitting next to me.  The call goes through but neither one of us could hear the other.  I checked to make sure bluetooth was off.  It is.  I can FaceTime with no problem.  I can listen to music with speakers and headphones.  I have a life proof case and I took that off to make sure the receiver wasn't blocked by anything.  I have turned the phone off and back on.  Thank you for responding and hope you have a solution for me.