National audienceIn this paper, we present a complete system for audio indexing. This system is based state-of-the-art methods of Speech-Music-Noise segmentation and Monophonic/Polyphonic estimation. After those methods we propose an original system of superposed sources detection. This approach is based on the analysis of the evolution of the predominant frequencies. In order to validate the whole system we used different corpora : Radio broadcasts, studio music and degraded field records. The first results are encouraging and show the potential of our approach which is generic and can be used on both music and speech contents