Hi i have an iPhone 5C the unit recently developed and issue where i cannot hear the party i called and they cannot hear me, however when i make a FaceTime video & audio call everything works fine so that rules out mic & speaker issue. I updated to latest IOS and erased and restored to factory still same issue. Several cold boots and normal reboot did nothing. Has anyone had any success with this problem please help. I did google it and others have ran into this problem but i can't seem to find any valid solutions.