Why can't I hear people on calls and why can't they hear me?

[angelgal13]

i cant Hear them and they cant hear me?

I got my Samsung galaxy s4 last Christmas. Its up to date with updates, and i'm having a problem. Since yesterday, I cant hear the other person and they cant hear me, not even on speakerphone or with headphones. I REALLY dont want to factory reset. I need to try everything else first. I have taken the battery out and restarted it several times.