Calling: other party does not hear me
When calling someone, the other party does not hear me at all (I hear them fine, always), or sometimes only during the first seconds. Facetime always works fine both ways, video and audio.
I have shut down the iPhone and did a restart, no avail. I did a complete restore, no avail. Noone I asked (friends, Apple dealer) has encountered the problem before.
(Of course I still have enough credit to make calls.)
Has anyone encountered this before? Has anyone any suggestion that will help me in diagnosing?
(I read similar questions, but I added that Facetime works fine.)
Thanks in advance.
iPhone 4, iOS 6.1.3