Abstract: A multi-pulse speech coder uses synthetic filters for generating crosscorrelated signals without pitch prediction and autocorrelated signals with pitch prediction. These signals are used as a basis for calculations to detect the correlations between the signals with pitch predictions and input speech signals.

Abstract: The apparatus has encoder and decoder units. The encoder unit is arranged such that a pulse sequence for minimizing the difference between an input image signal and a synthesized signal obtained by supplying the pulse sequence to a transmitting synthesizing filter is calculated and the pulse sequence is encoded and transmitted. The decoder unit is arranged such that the signal received from the encoder unit is decoded, a decoded signal is supplied to a receiving synthesizing filter and the receiving synthesizing filter generates a decoder image signal corresponding to the input image signal.