The introduction of the digital terrestrial television (DTT) around the world brings new problems to the television audience measurement process. In a multisignal context, with the emergence of new contents and squarely in front of the contemporary technological convergence, the correct representation of the viewing behaviors faces methodological challenges. New methodologies (Audio or Video Matching, Water Marketing) are needed in order to measure the digital television audiences. The measurement using audimeters enters a new era, facing the dual challenge of analog and digital measurement in a mixed television broadcast.