The U.S. Department of Defense
Digital Voice Processor Consortium

 T&E Committee | Directions to Meeting Sites

 MELP Implementation Recommendations
 The Effects of Tandeming on Voice Quality and Intelligibility
 Human vs. Machine Speaker Identification with Telephone Speech

Welcome to the DDVPC Homepage

The Department of Defense Digital Voice Processor Consortium(DDVPC) was  chartered by the Assistant Secretary of Defense for Command, Control, Communications, and Intelligence in the early 1970's. Its goal is to implement efforts to cooperatively provide secure digital voice communications to U.S. civilian and governmental agencies. The membership of the DDVPC spreads across both military and civilian U.S. government agencies. The purpose and content of these pages are designed to provide public access to information concerning the DDVPC's past and present efforts as well as support intercommunication between and among DDVPC members and government agencies interested in secure digital voice communications. More information concerning the responsibilities of the DDVPC can be found in The DDVPC Charter.

DoD Narrowband Voice Coder Algorithms:    

The Test & Evaluation Committee

The Test and Evaluation Committee (TEC) has representatives from the Army [external link],Navy [external link], Air Force, and the National Security Agency (NSA[external link]). The TEC has recommended several digital voice algorithms, including LPC-10, FIPS Pub. 137, a 2400bps standard, and CELP, FS1016, a 4800bps standard. More information concerning some of the coder algorithms evaluated by the DDVPC TEC may be found on the pages pointed to by the the following links. More information concerning the TEC and its current efforts may be found on theT&E Committee webpages.

A Proposed New 2400bps Federal Standard Voice Algorithm Announced

In 1992 The DDVPC, with input from the user community, began an effort to  replace the current 2400bps algorithm (FIPS Pub. 137, LPC-10) with a higher quality algorithm that could replace LPC-10 in older equipment and be incorporated into systems under development. The goal was to provide an  interoperable 2400bps algorithm that met or exceeded the performance of the current 4800bps federal standard (FS1016, CELP) and could operate on a single  1996-based digital signal processing device. After analyzing the performance and complexity measures of seven candidate algorithms, the Mixed Excitation Linear  Prediction (MELP) algorithm was selected by the TEC as the recommended new  federal standard algorithm for 2400bps voice communications. The MELP algorithm was jointly developed by Texas Instruments, Inc., Atlanta Signal Processors, Inc., and NSA.
More information concerning the test and evaluation process used for selection of the new 2400bps standard, including papers and test results presented during a special session at ICASSP 1996 in Atlanta GA.and sound samples may be found here: New FS 2400bps Test Results
The June 12, 1997 draft of the Federal Information Processing Standards Publication (FIPS PUB) for MELP may be found at:MELP FIPS PUB Draft[external link]

 This website is sponsored by ARCON Corporation for the DDVPC and as such must conform to DoD policies concerning websites. Please read this disclaimer for more information.

Comments concerning design and content of these pages  should be sent to info@arcon.com. This page was last updated on 31-Oct-2001.