A real time digital vocoder which has 2400 b/s data transmission rate

has been developed The speech quality of the vocoder is excellent

and it can be used in low bit rate speech communications. Based upon the acoustics of speech and information theory of chinese characters

we have designed a 2400 b/s digital channel vocoder by means of the simulation in a general-purpose computer and implemented this vocoder hardware by TTL small and medium scale integrated circuits. The listening tests have proved that synthetic speech intelligibility and naturalness are both satisfactory. Moreover

hardware is. simple. Thus it can be adapted for communication engineering.