Acoustic indexing for multimedia retrieval and browsing

This paper reviews the Video Mail Retrieval (VMR) project at Cambridge University and ORL. The VMR project began in September 1993 with the aim of developing methods for retrieving video documents by scanning the audio soundtrack for keywords. The project has shown, both experimentally and through the construction of a working prototype, that speech recognition can be combined with information retrieval methods to locate multimedia documents by content. The final version of the VMR system uses pre-computed phone lattices to allow extremely rapid word spotting and audio indexing, and statistical information retrieval (IR) methods to mitigate the effects of spotting errors. The net result is a retrieval system that is open-vocabulary and speaker-independent, and which can search audio orders of magnitude faster than real time.