iPhone 4S, iOS 5.0.1 and a small microphone problem

  I've had an iPhone 4S for a few months and I've been criticized more than once for not saying anything when I answer the phone, but the blame doesn't fall on me. Every time I accept a phone call and put the terminal to my ear, I answer, but my interlocutor doesn't hear the first words I say, so I have to say them again after a few seconds. Not all interlocutors reproached me for this, but a good part of them do and I blame it on the microphone in the iPhone 4S terminal, which, in my case, does not record the words spoken in the second immediately after accepting a call.

  Considering that iOS 5.0/5.0.1 had extremely many problems with calls on iPhone terminals, I'm coming to ask you if you have experienced something like this with your 4S or with any other iPhone model running iOS 5.x.