Second International Conference on Spoken Language Processing (ICSLP'92)

Banff, Alberta, Canada
October 13-16, 1992

Design and Performance of HARC, the BBN Spoken Language Understanding System

Madeleine Bates, Robert Bobrow, Pascale Fung, Robert Ingria, Francis Kubala, John Makhoul, Long Nguyen, Richard Schwartz, David Stallard

BBN Systems and Technologies, Cambridge, MA, USA

In this paper we describe the design and performance of a complete spoken language understanding system currently under development at BBN. The system, dubbed HARC (Hear And Respond to Continuous speech), successfully integrates state-of-the-art speech recognition and natural language understanding subsystems. The system has been tested extensively on a restricted airline travel information (ATIS) domain with a vocabulary of over 1000 words. In this application, the system functions as an electronic airline guide, searching a database to answer questions posed by the user. HARC is implemented in portable, high-level software that runs in real time on today's workstations to support interactive online human-machine dialogs at a very comfortable pace. No special purpose hardware is required other than an A/D converter to digitize the speech. The system works well for any native speaker of American English and does not require any enrollment data from the users. HARC has shown consistently high performance in formal evaluations on the ATIS domain. At the February 1992 DARPA-sponsored tests administered by the National Institute of Standards and Technology (NIST), the HARC system gave the highest speech recognition and overall understanding performance of all participating systems.

Full Paper

Bibliographic reference.  Bates, Madeleine / Bobrow, Robert / Fung, Pascale / Ingria, Robert / Kubala, Francis / Makhoul, John / Nguyen, Long / Schwartz, Richard / Stallard, David (1992): "Design and performance of HARC, the BBN spoken language understanding system", In ICSLP-1992, 241-244.