The disclosure relates to a method for transmitting an item of information in a communication channel linking a transmitter to a recipient, the method including the following successive steps: the determination, by the transmitter, of a first intelligible sound signal representative of the item of information to be transmitted, the acoustic processing, by the transmitter, of the first sound signal so as to produce a second sound signal unintelligible to the recipient, the transmission of the second sound signal from the transmitter to the recipient, the transmission of the first sound signal from the transmitter to the recipient, the transmission of the first sound signal being triggered by the transmission of the second sound signal, the second transmission of the second sound signal from the transmitter to the recipient, the second transmission of the second sound signal being triggered by the transmission of the first signal.