this counter determines the number of zero crossings of the infinitely clipped speech pattern eight bit binary counter 87 counts the number of interval reversals which are represented by the pulses at the output of or gate 83 the count of the zero crossover counter 85 is preset to a count of minus 1 and the time interval reversal counter 87 is preset to a count of positive 1 each of these counters is of conventional design and can be easily obtained commercially the output of zero crossover counter 85 is coupled to an eight bit arithmetic unit 91 which computes the following quantity arithmetic unit 89 receives the output of the time interval reversal counter 87 and calculates the following quantity the output of the arithmetic units 89 and 91 are coupled to a digital comparator 93 which determines whether the quantity 5 tir 1 is greater than or equal to 3 i 1 this output is coupled to or gate 95 and will be utilized as will be seen hereinbelow to classify the phonemes a and this if the quantity 5 tir 1 is less than 3 i 1 the speech recognition system of this invention will indicate the occurrence of an provided of course that the other aforementioned criteria for detecting are satisfied the arithmetic comparator units are not disclosed herein in detail since such circuits are well known to those skilled in electronic circuitry refer now to fig3 which is a logic diagram for determining whether the number of zero crossings of the infinitely clipped input voice signal is equal to 4 6 8 or 10 the binary coded outputs from the eight bit counter 85 designated by the numerals 101 108 are connected to the associated inputs 101 39 108 39 of.