The invention comprises a method and apparatus for reducing the noise generated by compressors, including Roots-type blowers. The invention has particular use for reducing noise generated by compressors used in mechanical ventilators, though the advantages thereof may be realized in many different applications. One embodiment of the invention comprises a noise-attenuating gas flow path for a compressor contained in a portable ventilator housing. In one embodiment, the gas flow path comprises a plurality of chambers interconnected by flow tubes. The flow path is folded so as to fit into the limited space of a portable ventilator housing. The dimensions of the chambers and the flow tubes are selected so that an impedance mismatch is created between the chambers and the flow tubes. In one embodiment of the invention, the flow path comprises one or more perforated tubes located in one or more of the chambers. The perforated tube has a port through which gas is accepted and at least one exterior tube through which gas exits. Impedance mismatches are created between the inlet chamber and the exterior tubes and between the exterior tubes and the chamber in which the perforated tube is located, which are useful in attenuating noise. One embodiment of the invention comprises a noise attenuating mounting system for a compressor. The mounting system comprises flexible mounts that cooperate to dampen vibrations generated by the compressor.