Hey Christy
Forget about reinstalling and all the scripted bull. I did all of this and still did not help. I even told them I have been an Apple Distinguished Educator since 2001 and know what I am doing and talking about. Nothing they recommend works. I am certain it is a fault on some, not all, phones. I just don't know what and Apple, as they are, refuse to admit it. I understand that there are sometimes errors in mass production. I just wish they would have the balls to be honest, stand up, and admit it. At the moment, my like for the Apple, the company, is inversely proportional to my like of their products. :-)
I would suggest downloading PHONE DIAGNOSTICS from the App Store. This allows you to test everything but more importantly, it allows you to test every microphone individually across a range of frequencies and lets you know if they pass or fail on each frequency. I ran this on my phone and it consistently failed the same 2 microphones across all frequencies. I then used this as evidence there was a fault when I returned it for a new phone.
Good luck
