The application discloses a noise attenuating system (100, 200, 300, 400, 700, 800) for use with a positive airway pressure system providing a flow of gas, comprising: an expansion chamber (140, 240, 340, 434, 740) having a volume an intake tube (115, 215, 315, 415, 715, 815) having an inlet (117, 217, 317, 410, 717, 812) and outlet port or portion separated by a length, wherein a portion of the inlet port or portion extends outside of the expansion chamber and either: a noise attenuator (110, 120, 170, 210, 220, 223, 224, 226, 228, 232, 270, 320, 411, 413, 422, 423, 424, 425, 426, 428, 431, 720, 722) having a bottom and protruding sidewall forming a cavity, wherein the noise attenuator is positioned near the inlet portion of the intake tube such that a portion of the intake tube extends into the cavity of the noise attenuator or: an acoustic deflector (110, 120, 170, 210, 220, 223, 224, 226, 228, 270, 232, 320, 411, 413, 422, 423, 424, 425, 426, 428, 431, 720, 722) positioned near the outlet port or portion of the intake tube, wherein noise is deflected away from the outlet port or portion of the intake tube. The application also discloses positive air pressure apparatus (100, 200, 300, 400, 700, 800) comprising a housing (180, 480, 880, 884), first and second acoustic chambers, an intake vent or port (125, 225, 410, 812) in the first chamber, an inlet port or tube coupling the first and second chambers, a noise attenuator in the first chamber, and a blower unit (150, 250, 350, 440) in the second chamber.
