The invention concerns a method for transmitting in an area information items in the form of sound waves representing a signal X, through a loudspeaker enclosure, said method comprising a step of setting up a public address system which consists in applying to the input of the loudspeaker enclosure an electric signal P=W. The control circuit senses the current through the synthetic rectifier, and in particular is responsive to the rate of decrease of the current so as to anticipate when the current goes to zero and turn off at that instant. In addition, the design of the FDC-MSR powered fuel cell makes it possible to capture good concentrations of CO2 for sequestration or use in other processes. An enable signal capable of switching the current switch is provided. The tag includes at least one dynamic indicator that may be changed based on one or more predefined rules upon transmission.