IPhone 4 doesn't have voice on calls.

[Time2105]

When making or receiving calls, no one can hear me, while I hear them perfectly fine. I tested the hardware, mics record properly, so that's not the issue. I back-up my stuff then did a factory reset, didn't work... Any advice on what to do next??

 

[McGiord]

Test it with the apple in earphones mic, and see if they can hear you when talking over the mic.
Restart the iPhone and try again.
Double check the mute function is not active.

 

[Time2105]

Thanks for your response...

I tested with earphone mic, still not working, and mute is off...

 

[Time2105]

Bumping this up, as my issue is still not resolved. I vainly hoping the ios6 update might solve my issue, but it's not very likely.

Any other ideas that could help me turn my iPhone back into a phone?

 

[Time2105]

Issue resolved!!

Turns out the phone was dropped one to many times and a little soldered contact was loose. All I had to do was open it up and palce a tiny piece of cardboard in a particular spot. I found this video which helped my fix the problem.
http://www.youtube.com/watch?feature=endscreen&NR=1&v=0jhWxYTVxe4

Hope this can help someone else!