this came up recently, when i call a person i can hear them pick up but after a while i can't hear them anymore, nor can they hear me. when i turn on my speakers i still can't hear them. Microphone still works (made a recording to test) and my speakers still work (can play music through them) also, when i end the call i hear the ending "beep" through my front speaker so those should still be active as well. could it be my SIM card or anything? I don't know...or a software issue? I read something about upgrading the radio and I was wondering if it could have anything to do with that, anyways, I'm currently stuck. Rebooting the phone allows me to make 1-2 more calls without problems then the problem reoccurs, very strange. I'm on the latest MIUIandroid ROM, I have the problem since 3 updates ago (approx).