Opportunities for Advanced Speech Processing in Military Computer-Based Systems

This paper presents a study of military applications of advanced speech processing technology which includes three major elements: (1) review and assessment of current efforts in military applications of speech technology; (2) identification of opportunities for future military applications of advanced speech technology; and (3) identification of problem areas where research in speech processing is needed to meet application requirements, and of current research thrusts which appear promising. The relationship of this study to previous assessments of military applications of speech technology is discussed, and substantial recent progress is noted. Current efforts in military applications of speech technology which are highlighted include: (1) narrowband (2400 b/s) and very low-rate (50-1200 b/s) secure voice communication; (2) voice/data integration in computer networks; (3) speech recognition in fighter aircraft, military helicopters, battle management, and air traffic control training systems; and (4) noise and interference removal for human listeners. Opportunities for advanced applications are identified by means of descriptions of several generic systems which would be possible with advances in speech technology and in system integration. These generic systems include: (1) integrated multi-rate voice/data communications terminal; (2) interactive speech enhancement system; (3) voice-controlled pilot's associate system; (4) advanced air traffic control training systems; (5) battle management command and control support system with spoken natural language interface; and (6) spoken language translation system. In identifying problem areas and research efforts to meet application requirements, it is observed that some of the most promising research involves the integration of speech algorithm techniques including speech coding, speech recognition, and speaker recognition. 1 I n t r o d u c t i o n and S u m m a r y This paper is the result of a study of military applications of advanced speech processing technology which has been undertaken with the following goals: (1) to *This work was sponsored by the Department of the Air Force and the Defense Advanced Research Projects Agency. review and assess a representative sampling of current efforts in military applications of advanced speech processing technology; (2) to identify opportunities for new military applications, or further development of current applications; and (3) to identify areas where improvements to speech processing technology are needed to address military problems. The intention is to outline a fairly broad range of applications, opportunities and speech technology areas; however, the coverage is not intended to be fully comprehensive, nor to be very detailed in any particular area. Numerous references are provided, on other survey articles, on specific applications and technologies, and on pertinent research efforts. An historical point of reference for this paper is the 1977 paper by Beek, Neuburg, and Hodge [10], which assessed speech recognition and speech processing technology for military applications. A great deal has been accomplished since 1977 both in speech technology and in applications, but the generic application areas identified in that earlier paper generally remain as relevant now as they were in 1977. The organization of this paper is as follows. A framework for the paper is first developed by outlining key speech technology areas and key categories of military applications, and identifying which technologies are needed for each category of application. Several previous assessments of military applications of speech technology are then reviewed, and the relationship of this study to those assessments is discussed. A representative sampling of current work in the key military application areas is then summarized and assessed. A set of opportunities for advanced applications are then identified and described; the approach is to describe several generic systems which would be possible with advances in speech technology and in system integration. This description Of application opportunities is followed by a brief outline of areas where improvements are needed in speech technology to meet the challenges of military applications, and notes several major technology development efforts which are in progress. Finally, conclusions and areas for further study are discussed.