you have a faulty screen, I had the same problem when i purchased a cheap one on eBay. I could not get any sound during calls and the other person could not hear me either. I put the old cracked screen and everything worked fine. I complained to the seller and got a refund, I brought another one which was a bit more expensive but it worked fine.
its a hit and miss i have found with aftermarket LCD/Digitizer screens some suppliers are cheap but somewhere in the manufacturing process something got screwed up, other times its good.