Video Mail Retrieval using Voice: An Overview of the Stage 2 System

This paper outlines the Video Mail Retrieval (VMR) project at Cambridge University. The goal of the VMR project is to develop an application for the retrieval of spoken documents in multimedia systems. Speech documents pose a particular problem for retrieval since the contents are unknown. The VMR project seeks to address this problem by combining state-of-the-art speech recognition with established document retrieval technologies to provide an effective and efficient retrieval tool. Experimental results with a small spoken message collection show that retrieval precision is somewhat dependent on the generality of the acoustic modelling used. For talker-dependent acoustic modelling retrieval performance is around 95% of that observed when text transcriptions of the same files are used. However, even with incorporation of completely open-user talker-independent acoustic models, retrieval performance of about 75% of text can be obtained.