A Digital Channel Vocoder
Theodore Bially, W. Anderson · IRE Transactions on Communications Systems · 1970
An all digital realization of a channel vocoder is described, including both computational algorithms and hardware structures. The machine, constructed almost entirely of digital elements, operates at a 2400 bit/s rate and produces synthetic speech, whose intelligibility and speaker recognition properties are comparable to those of an average telephone line. The extensive use of integrated digital circuitry allows size and cost reductions that are not currently possible in conventional high-quality analog vocoder systems.