A warewash machine includes a housing defining a chamber for receiving wares, the chamber having at least one spray zone, a wash spray system for spraying wash liquid onto wares and a rinse spray system for spraying rinse liquid onto wares. At least one ultrasonic transducer is located for detecting wares feeding into the chamber and/or for detecting wares within the chamber. A controller is associated with the ultrasonic transducer and configured to identify one or more of ware location, ware movement, ware size, ware shape and/or ware material based upon outputs from the at least one ultrasonic transducer. The controller is further configured to control at least one operating parameter of the machine based at least in part upon identified ware location, identified ware movement, identified ware size, identified ware shape and/or identified ware material.