I don’t know why they don’t offer this information on the countless amounts of inquiries that they have on this problem, but I’ve gone through all the motions myself and finally someone at the Apple Store was honest enough with me to tell me that they’ve started building the speakers into the screens, so basically bending your phone in the slightest fashion can screw up the speaker that you should be able to hear the other caller from. Apple is seriously slipping. They used to be top-notch. They used to build what was almost a bulletproof product and now they’re garbage. I’m actually dealing with this problem for the second time on a second phone and I’m thinking there won’t be a chance for a third time