Process for digitizing speech

Abstract

A process is disclosed for digitizing (more precisely encoding) speech for the purpose of reducing information rate and bandwidth relative to that of prior art means to digitize speech, while enjoying a high signal to noise ratio. Using the the same encoding techniques the process can be used for storage of speech and machine recognition of speech. The process depends on detecting audio waveform zero crossings and generating uniform pulses at the time of the zero crossings. The uniform pulses are created through a regenerative process and are independent of the actual waveform shape save the time of zero crossing. Transmission (or storage) of these uniform pulses permits reconstruction of highly intelligible speech. Ratios of times between zero crossings is used in a new technique for machine word recognition; said ratios allowing recognition regardless of the speakers actual speech rate.