WO 200289110 A UPAB: 20021212 NOVELTY - Silencer comprises microperforated components, and a sleeve or a cover (1) at least partly covering or surrounding a first large hollow space (2). Microperforated surface structures (3) provided inside the hollow space touch only on lines or at points so that a number of small hollow spaces (4) are aerodynamically and acoustically connected to each other. DETAILED DESCRIPTION - Preferred Features: The surface structures are made of metal and are provided as flat paths arranged in a zigzag or undulating manner. The surface structures are themselves small rounded or edged hollow spaces or irregular crumpled up hollow spaces. USE - For a motor vehicle. ADVANTAGE - The silencer can be easily taken part for cleaning and re-assembled.