BUILDING SPEECH RECOGNITION APPLICATIONS

In this tutorial we focus on the impact of grammars on the quality and success of speech recognition applications. Grammars used for speech recognition fall apart into 2 large categories: statistical grammars and finite state grammars. The statistical grammars on trained on huge example corpora, as might be available for dictation applications. In most command & control system the number of available example phrases is too small for such approach. On the other hand, if the application is concise enough, then it may be possible to construct a suitable semantic grammar for that particular application. A danger looming behind the corner, is that the grammar may not cover all possible dialogues and hence result in a poor application. However, the picture is not as black and white as it looks at first sight. A number of 'overspecifying' finite state grammars can be defined in between 'no grammar' and the cute compact semantic grammar. An increased design effort may lead to lower perplexity grammars, but at the same time have higher quality requirements in order to be fully functional. In the morning session we will review the general concepts required. In the afternoon session, a practical example will be worked out. Different groups will work on different - competitive - implementations. Finally the different designs will be informally evaluated against one another for effort, complexity and completeness.