Classification of general audio data for content-based retrieval

In this paper, we address the problem of classi®cation of continuous general audio data (GAD) for content-based retrieval, and describe a scheme that is able to classify audio segments into seven categories consisting of silence, single speaker speech, music, environmental noise, multiple speakers' speech, simultaneous speech and music, and speech and noise. We studied a total of 143 classi®cation features for their discrimination capability. Our study shows that cepstralbased features such as the Mel-frequency cepstral coecients (MFCC) and linear prediction coecients (LPC) provide better classi®cation accuracy compared to temporal and spectral features. To minimize the classi®cation errors near the boundaries of audio segments of di€erent type in general audio data, a segmentation±pooling scheme is also proposed in this work. This scheme yields classi®cation results that are consistent with human perception. Our classi®cation system provides over 90% accuracy at a processing speed dozens of times faster than the playing rate. Ó 2000 Elsevier Science B.V. All rights reserved.