Abstract
Processings for speech sound have been carried out in audio band such as spectrographic analysis, autocorrelation, infinite clipping, extremal coding and statistical representation. There is another possibility of processing the frequency shifted speech sigmal, because of the fact that S. S. B. signals contain the same information of the original speech signals. In this paper, we discussed theoretically and experimentally as to how much the essential information can be preserved in this processing. It was found out that this processing can be used for a new information source which has removed the redundancy of phase information with high intelligibility. Based on these results, we have developed speech band compression systems, new extraction systems of the speech parameters such as pitch and formant, and speech recognition system.
