I'm new to AT&T. When I make phonecalls, I hear a slight static background in the earpiece (like the old cell phone days), except when the person speaks, the static stops. Is this normal? It shows that I have all bars.
Does the problem occur when you are speaking to someone on a landline? Or a mobile phone? Sometimes it may be that the other person's reception is not well. Does it consistently happen with every phone call you make?
If it's a consistent issue that can easily be reproduced while at the Apple Store, I would take it over there and see about it getting replaced. I haven't had this problem though, and since no one else has chimed in it may be that the phone is defective. It wouldn't hurt to stop by the Genius Bar if it happens ALL the time (assuming you have one nearby).