My audio is dead to othe callers?

I have a problem with the Iphone 4 not transmitting my voice to other callers.I can record voice on the voice recorder, and hear myself in the ear phone. my audio is dead to other phones. Ive restored and backed up with no change. I reboot with no change, Any help, My son said accessibility in settings, but I didn't find a thing.

I can only think you are somehow activating the "mute" button during calls. Does this happen when you use the headphones with the mic built in, or only when you are holding the phone to your head?

The fact that you can record your voice on the voice recorder proves that the built-in mic on the iPhone works correctly, so I think we can rule out hardware as an issue.