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BELL SYSTEM TECHNICAL JOURNAL 



Fig. 4 — ^The vocoder as demonstrated. 



Circuit diagrams supply a shorthand for expressing the sahent fea- 

 tures of electrical circuits. In the next three figures comparative block 

 circuits will be shown for the human and the two electrical speech 

 synthesizers, tracing the communication from the origin of an idea in 

 the communicator's brain to final expression as speech. In each cir- 



