My iPhone 4 is currently having an issue with phone calls. I can hear the person just fine, but they cannot hear me. This is the phone itself, not headphones.
Take the phone to a AT&T store tell them your problem they will tell you what's up or get a outer box case put it on the phone and you get warranty from outter box cases just call the guys at outter box and say your phone got missed up while in the case and there you go new iPhone 4