There are sounds of struggle and survival on the tape recording.
"We didn't believe," said Bill Albracht. "We didn't think. We legitimately knew we were going to die that night."
There are also sounds of heroes.
Outnumbered 40 to one, Captain Albracht leads his troops on an amazing escape from Firebase Kate in Vietnam.
It's early November 1969, and Albracht is just 21 years old.
The young man from Rock Island finds himself in one of the most challenging positions in the Vietnam War.
He's also the youngest captain to command troops there.
"It had a profound effect on everybody who was there," he said.
Nearly 40 years later, he's unlocking a closet of suppressed memories to write, "Abandoned in Hell: The Fight for Vietnam's Firebase Kate."
"Some people say it's a minor miracle that you guys got out of there," he continued. "If you were there, it was a major miracle."
For his leadership during the absolute worst of times, he became one of the most highly decorated Illinois veterans.
He emerged as a leader and hometown hero although it took decades to revisit his war experience.
There were emotional moments during his third Silver Star ceremony in 2012.
"I have never felt that I was needed more, or have I ever been more scared," he said at the time.
At book signings across the country, Albracht is connecting with audiences.
He's inspiring conversations with fellow veterans and others about a war that few wanted to talk about.
"We were able to retell a battle that is so very, very typical of the good and the bad of Vietnam," he said.
Albracht talks about dark days at Firebase Kate.
They were running low on water, ammunition and completely out of luck.
It's reality for the reader and important to remember.
"So they know the bravery that was exhibited, not just on the ground, but in the sky above," he said.
It hits close to home as a history lesson that's cathartic for veterans.
"Everybody has a story," he said. "I was fortunate enough to put mine on paper."
At a Vietnam Veterans Memorial outside Jumer's in Rock Island, Albracht is thinking about his late friend.
He pauses to talk about Medal of Honor recipient John Baker.
"He stood taller than any man I ever met," Albracht said.
And he points out a brick from the notorious POW prison known as the Hanoi Hilton.
"This brick is placed as a tribute to all the POW's that endured," he read.
Albracht went on to a successful career in the Secret Service, where he served under six presidents.
These days, at age 66, he's a semi-retired security consultant in Illinois.
Looking back, Bill Albracht's book salutes fellow Vietnam veterans.
"The real heroes of the war didn't come home," he said.
It's a sad reality that still hurts nearly a half-century later.
"Those are the people that allow us to be here today," he said. "And those are the people that I always remember in my heart."
On this Veteran's Day, it's a heartfelt tribute from a proud soldier.