Abstract: A device for muffling the sound produced by a fluid in a duct, especially the sound produced in an intake pipe of a combustion engine, comprises a wall, whose inside defines a flow passage for the fluid. The device is at least partly tubular, i.e. it has two openings. At the outside of the wall (3) is arranged a plurality of chambers (4), each of which is connected to the flow passage via an aperture (7). The chambers (4) are bounded by the outside of the wall (3) as well as by bars (5, 6, 8) formed at the outside of the wall (3). The chambers (4) function in use as Helmholtz resonators. In addition, a device for the conduction of a fluid with the sound proofing device (1) described is presented.