An examination of three classes of ASR dialogue systems: PC-based dictation, in-car systems and automated directory assistance

Three classes of practical speech recognition dialogue systems are considered, starting with PC-based systems, specifically dictation systems. Although such systems have become very effective, they have not achieved mainstream use. Some reasons for this disappointing outcome are proposed. Speech recognition is now appearing in production cars. It is argued that the two most attractive in-car applications are for navigation systems and for dialing-by-name. The latter may be more suited to equipment that can be detached from the car and connected to a PC. After considering telephone applications in general, the importance of automated DA (directory assistance - also called directory enquiries or DQ in some countries) is established and its particular challenges are discussed. Among these are the size and dynamic nature of the databases accessed, and the variations produced by callers in naming a commercial/administrative entity whose number they are seeking. The advantages of a bottom-up phonetic speech recognition technique for automated DA are described. It is concluded that the combination of this technique and automatic methods for handling name variation makes automated DA, including access to business listings, a practical proposition.