A low noise exhalation port for a respiratory mask has a body including a proximal end operably connected to an internal area of the mask to vent carbon dioxide exhaled by a person from the mask, and a distal end. The venting device vents a gas out of the respiratory mask so as to substantially reduce inhalation by the person of the exhaled carbon dioxide. An exit passage portion is provided at the distal end and extends partially through the body and communicates with an exterior of the mask, the exit passage portion having a substantially regular cross-sectional area. An entrance passage portion is provided at the proximal end and extends partially through the body, the entrance passage portion communicating with an interior of the mask and further communicating with the exit passage portion, the entrance passage portion decreasing in cross-sectional area from the interior of the mask to the exit passage portion.