How do mufflers actually work? Are mufflers made of special sound-proof material?

Your exhaust system and mufflers in particular is very sophisticated. Technically, your muffler has baffled passages that the exhaust gases move through to muffle engine sound. But if you were to cut away your muffler, you d find some tubes with holes in them. Sounds simple, but inside your muffler, these elements work together to have the sound waves hit one another to reduce the noise. Your muffler is actually a finely tuned instrument.