Abstract: A coding and decoding system for video and audio signals includes means at the transmitter for deriving clock and internal timing signals from the video signal. The internal timing signals are utilized at the transmitter to provide digital audio data representative of the program audio signal. The digital audio data is derived by sampling the program audio signal during horizontal lines of the video signal. The synchronizing information in the horizontal and vertical blanking intervals of the video signal is suppressed and the digital audio data and data representative of a decoder clock signal are inserted in the horizontal blanking intervals. Vertical reference signal data is inserted into the vertical blanking intervals of the video signal as it is transmitted. At the decoder there are means for reconstituting the audio signal from the digital audio data.