Experiments with a pattern-matching channel vocoder

Preliminary results are reported on a pattern-matching vocoder experiment. In contrast to other reported approaches to this problem, the method employed involves a great deal of perceptual feedback from the experimenter, who incorporates patterns into the pattern set from a new sentence by first listening to the sentence as processed through the complete system. By identifying those portions of the processed sentence that have been degraded, he can augment the pattern set with only those frames that were degraded. The preliminary results indicate that a system with 500 patterns plus volume normalization, resulting in a 550 bits per second rate for spectral transmission, yields reasonably good synthetic speech.