Abstract: A method and apparatus for automatically identifying a program broadcast by a radio station or by a television channel, or recorded on a medium, by adding an inaudible encoded message to the sound signal of the program, the message identifying the broadcasting channel or station, the program, and/or the exact date. In one embodiment the sound signal is transmitted via an analog-to-digital converter to a data processor enabling frequency components to be split up, enabling the energy in some of the frequency components to be altered in a predetermined manner to form an encoded identification message, and with the output from the data processor being connected via a digital-to-analog converter to an audio output for broadcasting or recording the sound signal. In another embodiment, an analog bandpass filter is employed to separate a band of frequencies from the sound signal so that energy in the separated band may be thus altered to encode the sound signal.

Abstract: A method and apparatus for automatically identifying a program broadcast by a radio station or by a television channel, or recorded on a medium, by adding an inaudible encoded message to the sound signal of the program, the message identifying the broadcasting channel or station, the program, and/or the exact date. In one embodiment the sound signal is transmitted via an analog-to-digital converter to a data processor enabling frequency components to be split up, enabling the energy in some of the frequency components to be altered in a predetermined manner to form an encoded identification message, and with the output from the data processor being connected via a digital-to-analog converter to an audio output for broadcasting or recording the sound signal. In another embodiment, an analog bandpass filter is employed to separate a band of frequencies from the sound signal so that energy in the separated band may be thus altered to encode the sound signal.

Abstract: A method and apparatus for automatically identifying a program broadcast by a radio station or by a television channel, or recorded on a medium, by adding an inaudible encoded message to the sound signal of the program, the message identifying the broadcasting channel or station, the program, and/or the exact date. In one embodiment the sound signal is transmitted via an analog-to-digital converter to a data processor enabling frequency components to be split up, enabling the energy in some of the frequency components to be altered in a predetermined manner to form an encoded identification message, and with the output from the data processor being connected via a digital-to-analog converter to an audio output for broadcasting or recording the sound signal. In another embodiment, an analog bandpass filter is employed to separate a band of frequencies from the sound signal so that energy in the separated band may be thus altered to encode the sound signal.