VOICE IDENTIFICATION SYSTEM WITH NORMALIZATION FOR BOTH THE STORED AND THE INPUT VOICE SIGNALS

• US 3,770,891 A
• Filed: 04/28/1972
• Issued: 11/06/1973
• Est. Priority Date: 04/28/1972
• Status: Expired due to Term

• Current Assignee: Meguer V. Kalfaian
• Original Assignee: Meguer V. Kalfaian
• Inventors: Kalfaian, Meguer V.
• Primary Examiner(s): Cooper, William C.
• Assistant Examiner(s): Leaheey, Jon Bradford
• Application Number:
  US05/248,740
• Time in Patent Office: 557 Days
• Field of Search: 179/1SA,1SB,15.55R,1VS 340/148,146.3C 35/35C
• US Class Current: 704/250
• CPC Class Codes: G10L 15/00 Speech recognition G10L17/00 takes precedence
• CPC Class Codes: G10L 21/00 Speech or voice signal processing techniques to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility G10L19/00 takes precedence

Abstract

In an articulated phonetic sound wherein the information bearing group of resonances vary within different frequency regions in the sound spectrum, the detected signals derived from the group of resonances are constantly regrouped to a reference numerical region along the outputs of a plurality of numerically arranged channels in order that, the signals derived from the varying pitch frequencies are shifted to the output of the first channel (at high speed), while the signals derived from other frequencies are shifted to channel outputs by the same factors of multiplication from the first channel that the original frequencies differ from the pitch frequencies. The mutually related amplitude ratios of significant signals of the regrouped signals are then matched with prerecorded voiceprint signals of the individual to be identified.

Claims

1. In a voice identification system wherein the voice signals of a speaking individual to be identified are compared with prerecorded voice signals of the same individual, but wherein each group of resonances in the sound spectrum representing a segment of said voices vary within the pitch intervals of the speaking and prerecorded voices respective of each other, and in conjunction with variations in resonance-amplitude from pitch to pitch periods, the system for normalyzing said variations during said comparison, comprising first and second identical normalyzing systems for the said speaking and prerecorded voice signals, the first system comprising a plurality of band-pass filters for sub-dividing the resonances of the speaking voice sound waves;

a plurality of detecting means for deriving detected signals from said filters;

means for deriving a control signal (outputs of R-S blocks 17-19) from said detected signals which represent a segment of the speaker'"'"''"'"'s speech during a pitch time interval, and said control signal having a time period equal to said time interval;

a matrix comprising a plurality of signal regrouping combinations, each combination having been prearranged for regrouping said detected signals in a pitch time interval to a reference numerical region in a numerically arranged plurality of channels, in an order that, said control signal in the group of said detected signals is made to appear at a reference channel in said reference numerical region, and each one of said combinations having been prearranged for operation by said control signal, means for deriving pitch pulses from said speaking voice;

a plurality of signal-amplitude equalizers connected to said plurality of channels, a plurality;

of parallel coupling means connected from said reference channel to said amplitude equalizers;

coupling means from said pitch pulses to the amplitude equalizer of said reference channel for equalizing said control signal to a reference amplitude during the applied pulse period, whereby the signal amplitudes of the rest of the channels are controlled proportionally by said reference channel, and thereby establishing spectral and amplitude normalized detected signals at said plurality of channels, representing said first system; and

means for comparing said signal normalized channel signals of said first and second systems and deriving matching signals, which may further be combined with said control signals of said first and second systems for deriving a final decision signal that may be used to recognize the individual.

2. The system as set forth in claim 1, wherein said normalyzed signals from said plurality of channels of said first and second systems are applied to first and second inputs of a plurality of operational amplifiers, for obtaining said comparison signals;

a normally inoperative mixer means for mixing said comparison signals; and

a pulse generator of a predetermined frequency for operating said mixer means, so that discrete signals during said pulses may be obtained for interpretation and recognition of said individual.

3. The system as set forth in claim 1, wherein the center frequency responses of said plurality of band-pass filTers in said sound spectrum are arranged in a series of frequencies within harmonic intervals, each frequency of the series of frequencies in an interval corresponding to the harmonic of a frequency in the preceding interval;

and said matrix comprises a plurality of channels arranged in linearly sequenced numerical order, each channel output representing the output of at least one or more AND gates, the number of AND gates in each channel being equal to the number of the numerical location of that channel in said numerical order;

first parallel connections of the numerically corresponding first outputs of sad gates in the plurality of channels;

coupling means from said detected signals to said first parallel connected inputs, whereby each signal in a group may be coupled to any one of the first inputs of a number of channels for channel output selection during said control signal interval, second parallel connections of the second inputs in said AND gates in an arrangement that the second inputs of the AND gates in said channels starting from the channel located in the lowest numerical position in said numerical order are connected to successively advancing ones from the corresponding second inputs of the gates in the succeeding channels; and

coupling means from said control signal to said second parallel connections for establishing said signal regrouping.