The invention relates to a signal processing system comprising first electronic means for storing an input signal, second means for a real-time processing of the input signal thus stored, and third electronic means for storing the signal thus processed. This system is according to the invention, characterized in that said second processing means themselves comprise off-line signal enhancement means applied to said input signal and using available processing resources, not still used for real-time or on-line processing, for delivering an enhanced signal and storing it in said third means for storing the signal processed by the second processing means. The signal enhancement means may also comprise means for modifying said enhanced signal, said third electronic means for storing the processed signal being also able to store the enhanced signal thus modified, and the third electronic means for storing the signal processed may be provided for outputting the enhanced signal and/or the modified enhanced signal in real time.