Foreword - Voice Coding for Communications

INTRODUCTION: Since the introduction of 64 kbit/s A- and mu- law PCM in the international telecommunications network over 25 years ago, planners have been striving to introduce more efficient methods of converting 4 kHz voiceband signals into digital form for transmission. During recent years, these efforts have finally begun to bear fruit, not only for increased efficiency on digital transmission facilities, but on other applications as well, such as storage reduction in voice messaging systems. Success in these areas has been predicted on several factors: development of coding algorithms offerings better performance, more efficient digital signal processing techniques, and, of course, concomitant advances in VLSI technology.