3 NEW SPEECH CODERS FROM THE ITU COVER A RANGE OF APPLICATIONS

Many new speech coding standards have been created in the 10-year peri od 1987-1996. In this article the author reviews the key attributes th at determine what coder to select for different applications. The arti cle then focuses on three new speech coding recommendations from the I TU-T, namely G.723.1, G.729, and Annex A of G.729. They provide god co verage for a wide range of applications that have low bit rate require ments (i.e., from 5.3 to 8 kb/s). In addition to bit rate, the article reviews their delay, complexity, and performance. Also briefly review ed are the history of these standards, and what considerations influen ced the requirements each of these coders had to meet.