Please help, my iPhone won't turn on.

Today all audio on my phone stopped working. The phone still performed all its functions, it texted, made and received calls, played music, and allowed all apps. The issue was I couldn't hear anything, through the ear piece, headphones, or speakers. I tried to restore to factory settings, but once the phone reached the point at which it should have restarted, it simply stopped the process, and now will not turn on. Any advice?