CobraEd, I think you use the word absorb and I used the term "place to store air till it can sloooowly exit the muffler" to describe the same thing.
All the air that enters a muffler has to exit. Nothing is absorbed. A large muffler is quieter than a small muffler on the same car.
Stock vs glasspacks (Cherry Bombs).
The large muffler has more room to store the air till it exits the muffler.
Glasspacks have fiberglass in them and Flow Master uses metal baffles to slow down the air.
This same theory is used to build/design suppressors for firearms.
I don't design or build mufflers for a living, but this is what I think happens inside a muffler.
Dwight