Time compensation for speed of talking in speech recognition machines

A simplified version, but nevertheless complete system, of a phonetic typewriter which types in response to words spoken into a microphone has been described. One of the many extensions of the original system is a means for compensating for the effects of the speed of talking. Instead of transferring information into the spectral memory in fixed-time increments, as was done in the original machine, the transformation of information is determined from a correlation with significant changes in the speech spectrum with respect to time. In the improved machine, coincidence detectors compare the current with the preceding speech spectrum. No information is fed into the spectral memory until a significant change has been detected in the speech spectrum. The system provides an automatic time compensator for variations in the speed of talking in a speech recognition machine.