An inflator 10 of the present invention contains: a housing 12, a cold gas chamber 16 within the housing 12 for storage of a stored gas supply, a pyrotechnic chamber 18 within the housing 12, a pyrotechnic charge 20 within the pyrotechnic chamber 18, a wall 22 adjoining the cold gas and the pyrotechnic chambers 16, 18, a first orifice 24 defined in the wall 22 for passage of gas between the chambers, and a perforated flexible member 28 contained within the cold gas chamber 16, wherein the flexible member 28 is fixed about the orifice 24 for modulation or controlled variation of gas flow through the orifice 24.