INCORPORATING SEMANTIC KNOWLEDGE TO THE LANGUAGE MODEL IN A SPEECH UNDERSTANDING SYSTEM

The majority of the understanding systems follows an ar-chitecture based on two modules, a speech recognition mod-ule and an understanding module. Usually, only syntactic re-strictions are incorporated to the speech recognition module through the language model and the semantic restrictions are incorporated in the understanding module. In this work, we present an approach to language understanding where the se-mantic knowledge involved in the understanding process is in-corporated through an adequate definition of the language model of the automatic speech recognition module. Then, both the recognition and understanding processes incorporate semantic knowledge. An evaluation of the behavior of the proposed un-derstanding system in the framework of a dialog system is also presented. The results show that the use of semantic information in the language model of the speech recognizer provides for the best performance. 1