1. A method for producing a signal representing a phoneme sound contained in a stream of voice signals, said method comprising the steps of: (a) producing a first sequence of analog speech signals representing said voice signals; (b) delta modulating said first sequence of analog speech signals to produce a sequence of digital pulses representing phonemic information contained in said analog speech signals; (c) operating upon said sequence of digital pulses to detect major slope transitions of said analog speech signals; (d) measuring time intervals between predetermined ones of said detected major slope transitions; (e) computing a plurality of speech waveform characteristic ratios between predetermined ones of said time intervals; (f) comparing said speech waveform characteristic ratios with a plurality of stored phoneme ratios to determine if said speech waveform characteristic ratios match any of said stored phoneme characteristic ratios; and (g) producing a signal representing a phoneme sound corresponding to a matching one of said phoneme characteristic ratios.