Speech encoder/decoder with speech recording and reproduction functions

摘要

A speech encoder/decoder resets an adaptive differential pulse code modulation, ADPCM, decoder (4) according to a reset signal (122) from a reset signal generating circuit (19) upon switching of a reproduction mode signal (112). At the switching of the reproduction mode signal (112), one of an ADPCM code (120) read from a memory (8) and an ADPCM code (103) supplied on a transmission line is selected and supplied to the ADPCM decoder (4). Since the APDCM decoder (4) has had its output muted according to the reset signal (122), no noise is generated even when a discontinuity of ADPCM codes is caused at the switching of the reproduction mode. An ADPCM encoder (3) and the ADPCM decoder (4) can be commonly used both for recording and reproduction and for communication. Thus, a speech encoder/decoder with recording and reproduction functions is provided which consumes less power and does not generate noises upon a mode change-over.