Sound-proofing housing (31), which comprises a first housing part (41) having an intake opening (44) and comprises a second housing part (51) having a discharge opening, wherein a shaped part (61) arranged in the housing (31) is also provided, of which the flange seal (63) comes to rest between the housing parts (41, 51) when the housing (31) is put together. The acoustic emission generated by the fan is considerably reduced by a specific embodiment of the shaped part (61) with air passage openings and air-guiding devices.