LIMITED VOCABULARY SPEECH RECOGNITION CIRCUIT FOR MACHINE AND TELEPHONE CONTROL

• US 3,742,143 A
• Filed: 03/01/1971
• Issued: 06/26/1973
• Est. Priority Date: 03/01/1971
• Status: Expired due to Term

• Current Assignee: Mebenin Awipi
• Original Assignee: Mebenin Awipi
• Inventors: Awipi, Mebenin
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Leaheey, Jon Bradford
• Application Number:
  US05/119,551
• Time in Patent Office: 848 Days
• Field of Search: 179/1VC,1SA,1SB,1HF,9B,15.55R 324/77
• US Class Current: 379/355.09
• CPC Class Codes: G10L 15/10 using distance or distortion measures between unknown speech and reference templates
• CPC Class Codes: G10L 25/09 the extracted parameters being zero crossing rates

Abstract

Machine or telephone control by voiced commands is attained by translating the electrical signal derived from an acoustic signal or spoken word into a plurality of binary parameter waveforms each indicating sequentially the instantaneous condition or measurement of the corresponding parameter in terms of its being on either one side or the other of a preselected threshold or norm. A command output signal is generated only when the waveforms are found to have a particular sequence of binary parameter combinations that is acceptable to a sequential logic recognition circuit.

Claims

1. Speech recognition apparatus for machine control comprising, in combination, first means for translating audio speech into a corresponding electrical analog signal, second means for translating said analog signal into a plurality Of binary signals comprising, a first circuit including zero crossing counter means, frequency-to-voltage converter means and first comparator means in a first serial combination, amplifier means, envelope detector means and second comparator means in a second serial combination, said first and second combinations being connected in parallel relation, said electrical analog signal being applied to said combinations from said first translating means, said binary signals each having a waveform presenting a first and a second level, each of said levels in each of said waveforms being indicative of the magnitude of a respective preselected speech parameter as being either above or below a respective preselected threshold level of said last named parameter, said combinations of said second translating means being responsive to a transition from either one of said levels to the other in any of said waveforms to generate a distinctive signal indicative of said transition, and word recognition logic circuitry responsive to a combination of said distinctive signals for generating an output signal uniquely indicative of a word or command as determined from said audio speech.

2. Apparatus in accordance with claim 1 wherein said logic circuitry includes a system of secondary logic responsive to said output signal for the operation of a repertory dialer telephone set.

3. Apparatus in accordance with claim 1 wherein said logic circuitry comprises a plurality of series connected combinations of flip-flops, said combinations being equal in number to the number of words or commands to be recognized, the number of said flip-flops in each of said combinations being equal to the highest number of said transitions that occur in either of the binary waveforms associated with the corresponding one of said words or commands, an AND gate connected between each adjacent pair of said flip-flops, each of said gates having an input from the preceding flip-flop of said pair and from the outputs of said first and second comparators, and an additional AND gate connected between said comparators and a respective first one of said flip-flops, said last named AND gate having inputs only from said comparators and having an output to said last named flip-flop, said inputs to all of said AND gates being either direct or inverted in accordance with whether the binary waveform associated with the related word to be recognized and with a particular one of said last named inputs has undergone one of said transitions at an immediately preceding point in time, an output from the last flip-flop in one of said combinations of flip-flops signifying the reception of an associated spoken word or command.