An exhaust port assembly comprising a conduit carries a flow of gas. A vent assembly having a fixed exhaust area is provided on the conduit for venting a flow of exhaust gas from within the conduit to ambient atmosphere. The vent assembly is configured so as to minimize noise associated with the flow of exhaust gas passing to atmosphere, diffuse the flow of exhaust gas passing to ambient atmosphere over a relatively large area, and minimize the area occupied by the venting assembly on the conduit.