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

Soundwaves travel in relatively straight lines (each “part” of the wave at least). The waves hit a spongy material at an angle. Some of the energy is absorbed, there’s a bit reflected at a weird angle to the spongy material in the next block, it absorbs the rest.