Go and look for stories about how the airline pilot's union tried to prevent the tapes from being played for the family members. They were uncomfortable with the precedent of cockpit recordings being shared with anyone. They were overruled, and the tapes were played to the family members. Those stories are not difficult to find, so no whining that you can't find them or that it never happened.
So one of two things is true. The tapes exist and say what is basically stated above, or the tapes don't exist and all of the family members are in on the coverup.
The latter is so implausible as to be, literally, laughable.
A morning radio show in Pittsburg played an excerpt from the recorder, it was about 30 seconds of one of the hijackers talking to the control tower in Cleveland, saying they had a bomb on board. I'll see if I can find a link to it (if it hasn't already been posted, I'm only halfway through the thread).