Abstract: The air muffler is primarily designed to be carried by a snug fitting hood respirator adapted to fit over the head of a person and to dispense breathable air into the hood in a minimum quantity of at least four cubic feet per minute, with a controlled noise level not to exceed 80 decibels, and with varying air pressure of from 11 to 25 pounds per square inch. The muffler utilizes a non-absorbent porous resilient fibrous filter media within a tubular casing provided with a series of ports, with the casing located entirely within a bag made from a non-absorbent porous fibrous material. An air pocket is provided between the portion of the casing provided with the ports and the bag. The air is directed from the source through the casing where it is restricted as it passes through the non-absorbent porous filter media prior to escaping through the ports in the casing into the air pocket where the air is muffled and is finally discharged into the hood through the porous fibrous bag.