A resonator is disclosed which includes: a sleeve insert and an outer duct sealingly coupled to the sleeve insert. The sleeve insert has a wall with a first aperture in the wall at a first axial distance, a second aperture in the wall at a second axial distance, and a rib extending radially outwardly with the rib located between the first and second apertures. The outer duct sealingly couples to the sleeve insert proximate first and second ends of the inner sleeve and at the rib. The sleeve insert and the outer duct are formed of plastic materials which are coupled by welding or via o-rings placed on the sleeve insert. Cavities, in the vicinity of the apertures, are formed in the outer duct. The cavities, which are fluidly coupled to the sleeve insert via the apertures, attenuate noise.