An assembly including a compressor for a turbine engine, and a discharge system including a supply duct, one end of which is connected to the compressor, the duct being configured to collect therefrom a flow of air compressed by the compressor; and a pressure-reduction device including an inlet and an outlet, the inlet being connected to the other end of the supply duct, wherein the pressure reduction device includes a casing forming a volume between the inlet and the outlet, a porous material occupying the volume, and a device for holding the porous material within the casing, wherein the outlet has an open section allowing the upper air to pass through the open section of the inlet.