On the original moon landing footage on youtube, it's weird that there is virtually no background noise from the retro rockets ....?

You don't need a big engine to land on the Moon. The Lunar gravity is 1/6 that of Earth, so the engine was sized accordingly. The Astronauts were also wearing their spacesuits with microphones built into their helmets. Those spacesuits were pretty good at filtering out the outside noise.

As far as the 2.6 second delay, keep in mind that the recording was made on Earth. There wouldn't be any lag on the tape between the transmission from the Moon and Houston's response. Beside the conversation between the astronauts and the flight director the tape also includes the conversations between the flight controllers and the flight director. There were actually several conversations going on at the same time. You can clearly hear one of the flight controllers calling out the time before the fuel runs out during the final approach and landing.

Moon Landing Youtube

They were wearing their space suits during the landing, so you wouldn't expect much outside noise getting through. I've also listened to the recordings of the landings. There was no real two-way communication happening--each side was basically just reporting to the other, so I don't know how you can tell anyone what the delay time was.

There weren't "retro rockets" just one large flared bell engine. And if you haven't heard of noise canceling microphones, you need to look into them. As for the time of transmission and return, you might work really hard and connect a statement with its reply because most of the transmissions were updates - continuous reporting - not "Houston we have a problem"

no. the reason why is because of the microphones and what they pick up. and if they were not in any contact with the lander (like if they got a suit on)

you can't hear anything outside since it's... a vacuum. and there is no way for the sound to get to the microphones.

Depends how much the engine vibrated I guess. The descent engine was small compared to some rocket engines and wasn't firing into atmosphere so it probably had pretty stable combustion and not much vibration.

Still, I 'd say your observation is full of error. Even two guys standing side by side there would have to talk on Radio as sound propagation is ABSOLUTE ZERO, do you hear me? Armstrong & Buzz Aldrin in their space suits & helmets are operating in a perfect vacuum chamber there. Your Common-sense approach breaks down. You need to possess the wisdom, to when to suspend your judgement & listen to the Scientists.

not at all. noise-cancelling microphones are standard in aerospace. you want to hear what the astronauts are saying, not the sound around them.

the various systems of the apollo lm made enough whirring and gurgling noises that astronauts practiced sleeping in engineering test models on earth so they would be used to the racket they would encounter on the moon.

the footage on youtube is edited for round-trip delays. like, duh!

Oh crap, they're on to us! Quickly, deploy the teams to silence this threa-

Sound is made from variations in atmospheric pressure. that travels in frequencies within the atmosphere. No atmosphere to carry it, no sound.