How does sticking weirdly shaped foam blocks on the walls of a room make noise hard to hear from inside and out?

Question

How does sticking weirdly shaped foam blocks on the walls of a room make noise hard to hear from inside and out?

In: 13

Answer 1

Imagine throwing a ball at the flat, hard, wall. The ball is your voice. The ball will bounce off the wall and back to you.

Now imagine those foamy pyramid things on the wall. If you throw a ball at it, it will not bounce back at you.

This might be enough to convince you, but you might also ask: “but it’s just the foamy-ness that is stopping the ball from bouncing back, not the shape, so why is the shape a pyramid?”

Answer: Imagine the pyramid things are now made of hard materials like concrete. If you throw a ball at the pyramid things, when it hits a gap, it will bounce in-between the gaps and never back to you.

So both the foamy-ness and the shape of the pyramids help sound not bounce back at you.