I have an iPhone 4 16GB in white and 2 days ago my microphone started to not function. It worked on other things like videos and voice memos but it will not work on calls. It will only work using speakers or earphones. I don't really know what to do, I can't always use my speakers and I won't always have my earphones with me.
I had that happen doesent work during reg calls but works during speaker phone. The receiver is different then the music games and speaker phone. Long time ago I had this issue they replaced it.