Updated

The words were both painful and revealing to families of Sept. 11 victims, illustrating the final moments of United Airlines Flight 93 and the people aboard the doomed aircraft.

The only audible cockpit recording recovered from the four jetliners hijacked that day was played Wednesday for a federal jury deciding whether to execute conspirator Zacarias Moussaoui.

"I don't want to hear it. I deliberately did not go to court. I can't hear that tape," said Debra Burlingame, whose brother, Charles, was the pilot on the hijacked plane that crashed into the Pentagon.

"It mirrors what happened in my brother's cockpit," she said. "It's just too unbearable to hear the sounds of that slaughter."

There were 33 passengers, seven crew members and four hijackers aboard Flight 93 when it slammed into a Pennsylvania field on Sept. 11. On the recording, passengers and hijackers struggle in the cockpit for control of the plane; one man says, "I am injured."

That man is Tom Burnett, said his parents, who had already heard the recording along with other family members. "We are very sure that he led the effort to take the plane back," Burnett's father, Tom, said Wednesday.

Beverly Burnett said she wishes the tapes could be played outside the Virginia courtroom. The judge refused to allow that, although the Sept. 11 Commission previously played short segments during public hearings.

"We feel that everyone should know what went on in that plane and how horrible it was. I think they will understand what our son did on the plane."

For Burlingame, who attended most of Moussaoui's trial either in Alexandria, Va., or from a closed-circuit hookup in New York, the phase of the trial dealing with the attacks' impact was too painful to see in person.

"Your nightmares are vivid enough. To have them even more vivid, I can't put that on myself," she said.

Burlingame said she supported the decision not to release the audiotape outside the courtroom. But she said the testimony in the trial is necessary to show the world the consequences of terrorism.

"This is an opportunity for all of the world to see the face of the enemy," Burlingame said. "To me that is as important as the disposition of the case against Moussaoui."

The federal judge hearing Moussaoui's case had warned prosecutors earlier that too much emotional evidence about the terrorist attacks could imperil a death sentence on appeal.

Said Tom Burnett: "I'm sorry, jury, but you're going to have to face it like we did, and like the families of people on 93 and all the other airplanes."

In New York's federal court, a handful of people watching proceedings via closed circuit TV included Elsa Rensaa, a World Trade Center survivor who said that hearing the cockpit recording successfully debunked some conspiracy theories.

Rensaa said the proceedings clear up speculation that the U.S. Air Force shot down the plane.

"You could hear from the cockpit voice recorder that the hijackers flew wildly and erratically to get people away from the door," she said.

Clayton Patterson, another survivor, called the trial a chance to air key facts and dispel myths about Sept. 11.

"People really did try to defend the plane and make something happen," he said. "It makes you understand in your head this is what really happened."

The tape played in court began with a hijacker saying: "Ladies and gentlemen: Here the captain, please sit down keep remaining seating. We have a bomb on board. So sit."

The wife of Flight 93 pilot Jason Dahl said she believes passengers never heard that announcement. She said he probably cut off the public address system to the main cabin because his training.

"Even though you can hear it on the cockpit recorder, it was not an announcement made to the passengers. He thought he was, but he was actually making the announcement to the air traffic control towers," Sandy Dahl said on ABC's "Good Morning America."

She also said the cockpit recording shows her husband was alive moments before the plane crashed.

"All the reports in the press and the government had him dead in the first-class cabin on the floor before the plane was brought down," Dahl said in an interview published Thursday in The Denver Post. "I always knew he was alive and in the cockpit with the hijackers, and I haven't been able to say anything about it."

Dahl and other relatives signed agreements to not disclose what was in the recordings until the jury in Moussaoui's case heard them.