Robust Speech Recognition over Narrowband Communications Channels in Tactical Battlefield Environments (U)

(U) Currently, low echelon military commanders have no ability to directly access the remote Situation Awareness (SA) and Command and Control (C2) information contained in Battlefield Tactical Operations Center (TOC) databases. Previous attempts, using Speech Recognition(SR) over a Narrowband Communications channel using a coded speech signal have been unsuccessful. However, our research and testing has shown that, due to recent advances in the areas of narrowband Digital Speech Processing and SR, it is now possible to perform robust recognition of a useful vocabulary over narrowband tactical communications channels. (U) This paper describes an implemented and tested system which was designed to provide secure, bandwidth efficient, hands-free, automatic remote database access to commanders in the field. This system uses a COTS-based Digital Speech Coder with an advanced Noise Preprocessor to communicate over a narrowband IP-based tactical network into a database server. The server employs COTS-based Speech Recognition(SR) system components and a SQL-generator program to provide direct access into a TOC-type database. Queries made by the user are transmitted to the database over a coded Narrowband Communications Channel and the answers are spoken back to the user. (U) The experimental results of our implemented wireless, Voice over IP (VoIP) system show that the end-to-end system performance is quite good even in the presence of ambient tactical noises.