In this paper we propose a fast and robust watermarking scheme for digital audio signals that allows automatic identification of musical pieces transmitted in TV broadcasting programs. Usually watermark is used as a way for hiding information on digital media. The watermarked information may be used to allow copyright protection or user and media identification. In our application the watermark must be, obviously, imperceptible to the users to mantain the quality of the source, should be robust to standard TV and radio editing and its processing has to require a very low complexity. This last item is essential to allow a software real-time implementation of the insertion and detection of watermarks using only a minimum amount of the computation power of a modern PC. Simulation results obtained on a long set of subjective test prove the quality and the robustness of the proposed approach.