Abstract: Recognition of human speech is carried out by storing a template for each unit of speech to produce a dictionary of stored words and phrases. A given speech signal is converted to produce a template which is compared to the stored template to find the closest comparison. The word or phrase corresponding to the identified template is produced and displayed to complete the recognition of the speech signal. The speech signal is processed to produce two separate frequency components. The frequency components are processed to produce a DC signal proportional to the frequency of the frequency component. The frequency components are also rectified to produce amplitude signals corresponding to the envelope of the frequency components. The products [F.sub.1 ][F.sub.2 ] and [A.sub.1 ][A.sub.2 ] and ratios F.sub.1 /F.sub.2 and A.sub.1 /A.sub.2 of the pairs of frequency and amplitude signals are produced to generate a plurality of relational signals which comprise the templates corresponding to each speech signal.

Abstract: Voice pitch is detected by passing a speech signal from a microphone 10 through a filter array 20 to a summing amplifier 22. The summing amplifier 22 provides a composite signal of the acoustic components of the speech signal and this composite signal is input to a multiplier 26 and from the multiplier 26 to a multiplier 36 having an output connected to a comparator 42. The comparator 42 compares the output of the multiplier 36 with a hysteresis signal, then provides an output to a phase locked loop 46. The phase locked loop 46 provides a first voltage output in analog form to a bar graph display 50 and provides a square wave output that is applied to a frequency-to-voltage converter 52 for driving a digital display 54.