I was reading the transcripts of the cockpit voice recorder that reportedly came from Flight 93, and realized that something seemed very unusual. The cockpit voice recorder (CVR) is one of the "black boxes" that records the audio from a microphone in the cockpit of the airplane.

According to the transcripts from the Flight 93 CVR, voices of the passengers can be heard on the other side of the cockpit door, saying things about getting into the cockpit and "roll it," and apparent reference to a drink cart.

However, the question I have is this: How could the microphones in the cockpit pick up the sounds of the passengers voices through the closed cockpit door of Flight 93?

As an experiment, try this. Put your cell phone on the opposite side of a closed door, and record a voice message or call somebody. See how loud you have to scream before your voice makes it through the door to be heard on the message. You can even have somebody else hold the cell phone and speak into to it while you're talking on the other side of the door. This will give you a recording of the difference in volume between a voice near the cell phone's microphone, and the voice that's coming from the other side of the closed door.

Does it make sense at all that voices from the other side of the closed cockput door would be picked up by the pilot's microphone, especially inside of a jet airliner?

Or does it make more sense that these recordings, which have not been made public, were doctored to make it look like the passengers were heroes?

What makes the story of the cockpit voice recordings suspect is that the U.S. Government has not permitted the recordings to be made public. Instead, only the transcripts of the recordings were made public. Even the families of the passengers were only permitted very limited access to listen to this recording.