High-Quality 800-b/s Voice Processing Algorithm

摘要

The 2400-b/s linear predictive coder (LPC) is currently being widely deployed tosupport tactical voice communication over narrowband channels. However, there is a need for lower-data-rate voice encoders for special applications: improved performance in high-bit-error conditions, low-probability-of-intercept (LPI) voice communications, and integrated voice/data systems. As a result of continued research, the intelligibility of very-low-data-rate (600 to 800 b/s) voice processors has steadily improved, from the upper 70s about a decade ago to the middle 80s in recent years. This report presents a new 800-b/s voice-encoding method that produces an intelligibility score of 92 (measured by the Diagnostic Rhyme Test (DRT)). This high score compares favorably with that attained by the 2400-b/s LPC.