SVM classification using sequences of phonemes and syllables

Abstract

In this paper we use SVMs to classify spoken and written documents. We show that classification accuracy for written material is improved by the utilization of strings of sub-word units with dramatic gains for small topic categories. The classification of spoken documents for large categories using sub-word units is only slightly worse than for written material, with a larger drop for small topic categories. Finally it is possible, without loss, to train SVMs on syllables generated from written material and use them to classify audio documents. Our results confirm the strong promise that SVMs hold for robust audio document classification, and suggest that SVMs can compensate for speech recognition error to an extent that allows a significant degree of topic independence to be introduced into the system. © 2002 Springer-Verlag Berlin Heidelberg.