Sound-synchronised video system

A stream of unsynchronized audio signal, representing speech and video signal of a speaker, is processed by decoding (CD1) the signal, memorizing (in LT1) a plurality of visemes corresponding to phonemes in the audio signal, fetching from the plurality visemes corresponding to phonemes (from PR1) in the audio signal, and imparting a synchronism to the video signal and audio signal by applying the fetched visemes to the unsynchronized video signal of the stream in synchronism with corresponding phonemes in the audio signal of the stream. According to an embodiment, the fetching step includes fetching visemes of the lip movement. The system is suitable for use in a videophone.