Speech coding for telecommunications

The function of a speech coding algorithm is to convert an analogue speech signal into a digital form for efficient transmission over a digital path, or efficient storage on a digital storage medium, and to perform the complementary function of converting a received digital signal back to analogue form. The article reviews those speech coding techniques which are already being extensively used in telecommunications applications. As well as explaining the basic principles employed by these speech coding algorithms to achieve efficient digital encoding, examples of telecommunications services which use these algorithms are presented