An aide who called 911 requesting an ambulance to Defense Secretary Lloyd Austin’s house on New Year’s Day asked that the ambulance be discreet and “not show up with lights and sirens.” (Alberto Pizzoli/AFP/Getty Images)

(CNN) — An aide who called 911 requesting an ambulance to Defense Secretary Lloyd Austin’s house on New Year’s Day asked that the ambulance be discreet and “not show up with lights and sirens.”

“We’re trying to remain a little subtle,” the aide told the dispatcher in a recording of the call obtained by CNN through the Freedom of Information Act from the Fairfax County Department of Public Safety Communications.

“Yeah, I understand,” the dispatcher responded to the aide, whose name is redacted from the audio. The dispatcher explained that ambulances typically turn off their lights and sirens on residential streets.

The aide asked that Austin — whose name is also redacted from the call — be taken to Walter Reed National Military Medical Center.

The audio, first reported on by The Daily Beast, provides new insight into the defense secretary’s physical state at the start of what became a two-week stay at Walter Reed for Austin, who was experiencing complications from a December 22 procedure to treat prostate cancer.

Austin, the aide said, was not experiencing chest pain or feeling like he was going to pass out. He was awake and oriented, according to the audio.

While Austin and the aide’s names are redacted from the audio, the street name of the partially redacted address provided to the dispatcher matches Austin’s address.

While Austin was admitted to the hospital on January 1 — and the intensive care unit on January 2 — the public did not know about his health complications until January 5. It was later discovered that the White House, including President Joe Biden, had not been notified until January 4. Congress was not notified until January 5. The revelation has raised numerous questions about Austin’s compliance with notification requirements and transparency in the Pentagon.

Biden has since said that Austin’s delay in notifying him was a lapse in judgment.

The Pentagon’s inspector general has launched a review of whether the Pentagon has the appropriate policies in place to ensure an effective transfer of power and duties following Austin’s hospitalizations.

Austin’s doctors said last week that he had a “minimally invasive surgical procedure” on December 22, but on January 1 he was experiencing “nausea with severe abdominal, hip and leg pain,” and was found to have a urinary tract infection.

“Further evaluation revealed abdominal fluid collections impairing the function of his small intestines,” the statement from his doctors last week said. “This resulted in the back up of his intestinal contents which was treated by placing a tube through his nose to drain his stomach. The abdominal fluid collections were drained by non-surgical drain placement.  He has progressed steadily throughout his stay.”

Austin was released on Monday, and his doctors said in a previous statement that he is expected to “make a full recovery.”

“Secretary Austin’s prostate cancer was treated early and effectively, and his prognosis is excellent,” said the statement from Dr. John Maddox, trauma medical director, and Dr. Gregory Chesnut, director of the Center for Prostate Disease Research at the Murtha Cancer Center at Walter Reed. “He has no planned further treatment for his cancer other than regular post-prostatectomy surveillance.”