Patent ID: 7466231

Claim:
A self-checkout system including: a console for interacting with a user when the user is located within a spatially defined control zone, wherein the console records a request from the user for assistance in interacting with the console; an interface responsive to the console for receiving a first signal from a central communications unit indicative of an audible representation from a supervisor console in response to the request from the user; a processor responsive to the first signal for selectively defining a second signal, including an inaudible ultrasonic transmission; and an ultrasonic transducer responsive to the processor for propagating the inaudible ultrasonic transmission to provide only in the control zone the audible representation, wherein the ultrasonic transducer outputs the inaudible ultrasonic transmission such that inherent properties of air within the control zone distort the inaudible ultrasonic transmission to provide the audible representation, wherein the ultrasonic transducer is aimed at a region likely to occupied by a head of the user, wherein the ultrasonic transducer is positioned so as to provide the audible representation only to the single control zone with which the output transducer is associated, wherein the audible representation is substantially inaudible outside of the control zone, including substantially inaudible to other users in adjacent control zones.