IPhone hearing problem after updating software?

I updated to iOS 6.1.3 on iPhone 3GS and since then I can't hear while making or receiving calls with the iPhone. Please help me what can I do to start using the phone for calls

Ugh, my iPhone (and a few other people I know) have done the same thing. Mine started after using the headset jack for music. I looked around for an answer and most said to keep resetting it, but that never worked. I ended up getting another phone.