Text-Like Segmentation of General Audio for Content-Based Retrieval

Automatic detection of (semantically) meaningful audio segments, or audio scenes, is an important step in high-level semantic inference from general audio signals, and can benefit various content-based applications involving both audio and multimodal (multimedia) data sets. Motivated by the known limitations of traditional low-level feature-based approaches, we propose in this paper a novel approach to discover audio scenes, based on an analysis of audio elements and key audio elements, which can be seen as equivalents to the words and keywords in a text document, respectively. In the proposed approach, an audio track is seen as a sequence of audio elements, and the presence of an audio scene boundary at a given time stamp is checked based on pair-wise measuring the semantic affinity between different parts of the analyzed audio stream surrounding that time stamp. Our proposed model for semantic affinity exploits the proven concepts from text document analysis, and is introduced here as a function of the distance between the audio parts considered, and the co-occurrence statistics and the importance weights of the audio elements contained therein. Experimental evaluation performed on a representative data set consisting of 5 h of diverse audio data streams indicated that the proposed approach is more effective than the traditional low-level feature-based approaches in solving the posed audio scene segmentation problem.