Ответ:
truncated residual excitation linear prediction
An improved adaptive predictive coding (APC) algorithm, according to which not the entire residual signal is transmitted, but only its low-frequency part, where the bulk of the power is concentrated. The use of RELP allows you to reduce the transmission rate in the channel from 16 to 9.6 kbps without significantly reducing the speech quality. The main advantages of this algorithm also include the possibility of operating devices using it in conditions of strong background noise.