Muffler

Silencer comprises an outer wall (5) formed as a bellows (6) defining hollow chambers (7) with the inner wall (4). Openings (3) in the inner wall open into the hollow chambers. The outer wall and/or the inner wall are made from a material having a density of at least 1.5 g/cm3>, especially at least 2.0 g/cm3>. Preferred Features: The outer wall and/or the inner wall are made from a plastic material having salts or oxides of the metals with the atomic number at least 20, especially at least 50, and/or carbon black as filler. The outer wall and/or the inner wall are made from acrylate rubber.