9/11 Building 7

When a controlled demolition takes place, they use explosives to bring down a building right?
It makes a hell of a noise right?
Then why don't people play the audio for Building 7 when they and try to sell you controlled demolition for Building 7?
Can you figure out why they don't play the audio?
Have a listen and tell me what you notice or don't notice...

Hat tip unknown creator, credit at end of video