Silent anti-theft protection system for goods presented to the public

An anti-theft protection system for goods presented to the public, the system comprising a set of sensors (4) connected to the goods (5) presented to the public, the sensors being linked to a control unit (1), the control unit being capable of determining states regarding the goods, said states being at least a state of presence of the goods and a state of theft attempt and/or actual theft, the shift from a state of presence of the goods to a state of theft attempt and/or actual theft resulting, in the absence of inhibition of the detection for said sensor, in the control unit being set into alarm, said control unit comprising or being connected to a sonorous alarm generating means (7), characterized in that the control unit further comprises wireless transmission-reception means (8), and the system further comprises at least one portable wireless transmitter-receiver (2, 2′) capable of communicating (11) with the wireless transmission-reception means (8) of the control unit, and in that the system further comprises means adapted so that, upon the setting-into-alarm of said control unit, the transmission-reception means of the control unit provide for searching for the functional existence of at least one portable transmitter-receiver, during a determined maximum search time thanks to the sending of a search signal, the functional existence of a portable transmitter-receiver being recognized by the transmission-reception means of the control unit receiving a response sent by said portable transmitter-receiver after the latter has received said search signal, and so that, in the absence of response from at least one portable transmitter-receiver at the end of the determined maximum search time, the control unit activates the sonorous alarm generating means to produce an audible alarm.