Abstract: A laundry appliance includes a drum that rotationally operates within a tub. The drum defines a processing space for treating articles. A fluid delivery system selectively delivers wash fluid into the processing space. A hemispheric ultrasonic transducer is positioned proximate a base of the drum. The hemispheric ultrasonic transducer selectively directs waves of an ultrasonic frequency in a hemispheric radiating pattern through the processing space. The waves generate air bubbles within the wash fluid and the waves cause the air bubbles to implode and release micro air jets that are directed into the wash fluid for sanitizing the articles. The micro air jets act on the articles to loosen and remove foreign material therefrom.