Abstract: A muffler for silencing low frequency noise of gas inducting machinery. The muffler includes a buffer reservoir having an inlet and an outlet. The outlet communicates with the gas inlet of the machine. The buffer reservoir has a volume of between twenty and thirty times the displacement of the largest equivalent cylinder of the gas inducting machinery. For a single piston compressor this would be a volume of ten to fifteen times the effective cylinder displacement of the compressor. A convergent/divergent nozzle is connected to the reservoir inlet. The nozzle throat is specially dimensioned relative to the machinery to pass the gas through it to the gas inlet at a throat velocity in the range of Mach 0.7 to 1. A suitable preswirler may be connected to the inlet of the nozzle to reduce the pressure drop across the nozzle.