Circuit arrangement for recognizing spoken numbers

Abstract

Abstract 1,109,496. Automatic speech recognition. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 23 July, 1965 [29 July, 1964], No. 31454/65. Heading G4R. In apparatus for recognizing spoken words signals representing the words are tested at regular intervals for the presence of two component frequencies a store being set whenever the corresponding frequency is present and, at the end of the word, the outputs from the stores are combined to identify the word. The stores set depend upon the sequence in which the corresponding frequencies appear. The speech signal W, Fig. 1, is divided into a low frequency fundamental wave a and the high frequency wave b. The output from L.P. and H.P. filters are applied to Schmitt triggers which, when the signal reaches a certain value, set corresponding flip-flops. These are reset by timing pulses from a timing pulse generator so that the signal is tested repeatedly. The outputs of the flip-flops are combined in gates and five flip-flops are set according to the order of occurrence of the frequencies. " N ", " S " and " I ", Fig. 2, indicate groups of sounds, " NI indicating that the N sound appeared before the I sound and N2 indicating that it occurred after. The outputs from the five flip-flops are combined in gates designed to identify the word spoken. Storage flip-flops energize indicators. The timing pulses may be derived from local maxima of the speech signal.

Inventors

• 👤 Heinz Kusch

Bibliographic Details