Android Question

I have a Samsung Galaxy S4 on AT&T. I recently updated to Jelly Bean 4.3. Everything started out just fine after the update last week but yesterday my phone started acting awry. I am unable to play sounds or hear phone calls. My phone freezes when I open the Phone app. It tells me my audio files are unsupported. I have done a factory reset twice and wiped the cache partition a few times but nothing has changed. Can anyone offer up some advice?