PURPOSE: To eliminate erroneous components in a short time, by providing an HPF designating the lower limit of a reproduced frequency band as a cutoff frequency to the post-stage of a D/A converter and giving the HPF an analog signal of an adding output between a DPCM input and the preceding prediction signal.

CONSTITUTION: The HPF 4 takes the lower limit frequency f0 of a reproduced frequency band as the cutoff frequency and eliminates erroneous signal components included in the adding output. In an output signal of a D/A converter 3, the erroneous signal component is attenuated by the HPF4 as shown in a figure DS and erased after 1/f0. The analog signal in which the erroneous component is attenuated and eliminated is converted into a digital signal by an A/D converter 6, stored in a memory 1 sequentially as a prediction signal and applied to a signal processing section. Thus, a signal in which the erroneous component is eliminated after 1/f0 is outputted from an LPF5 as shown in a figure ES.