A fast lattice-based approach to vocabulary independent wordspotting
David A. James, S.J. Young · 2002
Practical applications of wordspotting, such as spoken message retrieval and browsing, require the ability to process large amounts of speech data at speeds many times faster than real-time. The paper presents a novel approach to this problem in which all of the stored audio material is preprocessed off-line to generate a phoneme lattice. At search time, putative word matches are found in this lattice using symmetric dynamic programming. The paper presents the details of the algorithms used and compares performance with a number of conventional approaches using a 20 keyword vocabulary on the DARPA Resource Management Task. The results show that the proposed method is very much faster yet performs acceptably compared to conventional systems which depend on keyword-specific training or prior knowledge of the test set vocabulary.>