In this diploma thesis we will describe audio clip analysis and classification system that we designed and developed as an add-on for Orange software. Orange is an open-source system, designed for data mining. It contains widgets for displaying and manipulating data, building predictive models and several other tasks. It does not, however, contain widgets for reading and processing audio clips. For this purpose, we built an add-on called »Audio-IJS« within which we developed eight widgets that enable audio manipulation as well as integration with other Orange widgets. The constructed widgets enable filtration, segmentation (cutting), spectral analysis, feature extraction, audio play as well as several other functions, necessary for connecting with other Orange widgets. The developed add-on enables the user a rapid creation of sophisticated analyses of audio clips.