Three basic development directions of speech coding were analyzed: extreme low rate speech coding, variable rate speech coding and uncompressed speech coding.Their application fields were given.

• 摘要简要分析了当前语音编码总体上三个大的发展方向：极低速率语音编码、变速率语音编码和不压缩语音编码，并说明了它们的应用领域。