perception of the source information when the source signal is applied to an appropriate output device, such as a speaker or a display...http://www.google.fr/patents/US5940135?utm_source=gb-gplus-shareBrevet US5940135 - Apparatus and method for encoding and decoding information in analog signals Recherche avanc???e dans les brevets Num???ro de publicationUS5940135 AType de publicationOctroi Num??