Noise reduction appliance

A noise reduction appliance for connection to, or integrally formed with, an outlet end of a blast nozzle, the blast nozzle having an outlet with a nozzle outlet diameter, wherein the noise reduction appliance comprises:

• an appliance body with a conduit formed therethrough, the conduit extending from an inlet opening of the appliance body to an outlet opening of the appliance body, the inlet opening of the appliance body having an inlet opening diameter substantially equal to the nozzle outlet diameter;
• and
• the outlet opening of the appliance body having an outlet opening diameter greater than the inlet opening diameter;
• wherein a radius of the conduit monotonically increases with distance, from the inlet opening to the outlet opening;
• and
• wherein the conduit between the inlet opening of the appliance body and the outlet opening of the appliance body defines a convex shape.