Abstract: The construction described is a resistive sheet type of duct liner or duct silencer; i.e., a liner or silencer in which acoustical flow resistance is concentrated in a thin face sheet separating the flow passage and acoustical cavity rather than in an acoustically absorptive packing material filling the acoustical cavity. The invention disclosed is means for applying inexpensive perforated facings, similar to those in a conventional packed silencer, to provide resistive sheets which are effective in terms of noise dissipation and in terms of self-noise (noise generated by flow through the flow passages).