Speech enhancement and coding in harsh acoustic noise environments

Recent advances in speech enhancement and noise pre-processing algorithms have dramatically improved the quality and intelligibility of speech signals, both in the presence of acoustic noise as well as in benign environments. The use of speech enhancement in combination with voice coding algorithms and applied to governmental wireless communications systems is an important application area. This paper will first introduce one such system, the 2.4 kbps US Government Military Standard mixed excitation linear prediction (MELP) speech coding algorithm coupled with a speech enhancement algorithm developed by AT&T Research Labs. Next, the paper presents a discussion of the test conditions and results, and provide an interpretation of these results. Finally, a general discussion of related issues and conclusions is presented