This audio of course had to pass thru a two-way radio. Radio waves can travel without an atmosphere, sound cannot. That made radio a must for space. Radio ham, Jack Yanosov and his co-workers at RCA in Camden had designed and built the radio system for the Apollo 11 craft and monitored it throughout the mission.
Most people remember the "one small step for man" line, but those were not the first spoken on the moon, nor the first spoken after Neil Armstrong opened the hatch and stepped out. His first words actually were "OK Houston, I'm on the porch." It was a few seconds later as his feet reached the surface that he said his most misquoted lines. More here.
Those words were sent by via VHF radio using Amplitude Modulation with a radio that was designed by Jack Yanosov. He had originally began his career on the RCA assembly line, and eventually worked his way up to be a lead project engineer. As he explained it, he didn't want to be on an assembly line all his life. So he enrolled at the Temple Technical School and took electronics engineering. He received his Associates degree in 1953 and was promptly drafted by the US Army for the Korean War.
His degree and background got him off the front lines and into more technical work. He had the right aptitude and the military gave him additional electronics training at Ft. Monmouth. He eventually was stationed at the White Sands Proving Ground, a missile range in New Mexico. It was there that he started getting involved in ham radio. He took his exam and received his amateur license with the calls KN2KEF.
After being honorably discharged, he went to Drexel University. He got his degree and drove back across the Delaware river for a Job at RCA at their Defense Communications Systems Division more than a few steps up from the assembly line. The NASA bio is here.