It's possible that the tape of Saddam was old, and that the voice was taped as well, and that the man pretending to be Saddam was lip synching, which might explain why he had to read from a tablet.
At any rate, this arctile also speculates that Saddam may have been dead for years and doubles are being used to make it appear that he is alive.
What is interesting though is that the man pictured on the right looks like the man that read from the tablet.