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US 4,378,469 AGranted
Human voice analyzing apparatus
AssigneeMotorola, Inc.
InventorBruce Fette
Life of this patent
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Abstract
The analyzing apparatus includes a ten stage, all-zero lattice digital filter formed on a single semiconductor chip. A partial correlation coefficient is derived in each stage of the lattice filter in improved coefficient circuitry and the analyzer provides the ten partial correlation coefficients, for a best sample from a plurality of samples, along with the amplitude (R.M.S.), and the residual energy, or the excitation. The correlator uses the products FB, F.sup.2 and B.sup.2, of the residual F and B signals.
Claims15
Voice analyzing apparatus including N partial correlation coefficient determining digital circuits for incorporation into an all-zero lattice digital filter so that each circuit receives a different pair of N pairs of forward residual and backward residual signals and provides a different one of N partial correlation coefficients, each of said circuits comprising:
- (a) digital multiplying means for receiving a pair of forward residual and backward residual signals and providing a first output signal representative of the forward residual signal multiplied by the backward residual signal, a second output signal representative of the forward residual signal multiplied by itself, and a third output signal representative of the backward residual signal multiplied by itself;
- (b) signal combining means connected to receive the second and third output signals from said multiplying means for providing a sum signal representative of the sum of the second and third output signals;
- (c) digital filtering means connected to receive the first output signal for providing a numerator signal and connected to receive the sum signal from said combining means for providing a denominator signal;
- (d) digital dividing means connected to receive the numerator and denominator signals for providing an output signal representative of the quotient of the two received signals;
- and
- (e) digital filtering means connected to receive the output signal of said dividing means for providing an output signal representative of one of the N correlation coefficients.
3 more elements
Voice analyzing apparatus including an all-zero lattice digital filter formed of N stages with each stage being connected to receive a different pair of N pairs of forward residual and backward residual signals and each stage producing a different pair of the N pairs, each stage comprising:
- (a) a partial correlation coefficient determining digital circuit including
- (1) digital multiplying means for receiving a pair of forward residual and backward residual signals and providing a first output signal representative of the forward residual signal multiplied by the backward residual signal, a second output signal representative of the forward residual signal multiplied by itself, and a third output signal representative of the backward residual signal multiplied by itself,
- (2) signal combining means connected to receive the second and third output signals from said multiplying means for providing a sum signal representative of the sum of the second and third output signals,
- (3) digital filtering means connected to receive the first output signal for providing a numerator signal and connected to receive the sum signal from said combining means for providing a denominator signal,
- (4) digital dividing means connected to receive the numerator and denominator signals for providing an output signal representative of the quotient of the two received signals, and
- (5) digital filtering means connected to receive the output signal of said dividing means for providing a filtered signal representative of one of the N correlation coefficients;
- (b) first and second digital multiplying means connected to receive the forward residual and backward residual signals, respectively, and each further connected to receive the filtered signal for providing a first product signal representative of the product of the forward residual signal and the filtered signal and a second product signal representative of the backward residual signal and the filtered signal;
- (c) first combining means connected to receive the forward residual signal and the second product signal for providing a forward residual output signal which sequentially follows the forward residual signal applied to said first combining means;
- and
- (d) second combining means including delay means connected to receive the backward residual signal and the first product signal for providing a backward residual output signal which sequentially follows the backward residual signal applied to said second combining means.
7 more elements
A method of analyzing human speech in the form of a digital signal, F.sub.R, to provide N correlation coefficients, K.sub.1 through K.sub.N, comprising the steps of:
- providing a multiplier having X and Y inputs, a product output, and a divide by C or shifted product output, a divider having numerator and denominator inputs and a multiply by D or shifted quotient output, an adder/subtractor having A, B and -B inputs, a combined output and a divide by E or shifted combined output, and a plurality of temporary storage units each reset to zero prior to starting the method;
- inputting F.sub.R into the X input of the multiplier, into an F.sub.R temporary storage unit, and into a first temporary storage unit;
- inputting a signal, B.sub.R, from a B.sub.R temporary storage unit into the Y input of the multiplier and initiating a multiplication process;
- inputting a signal, L.sub.N, from a L.sub.N temporary storage unit into the B and -B inputs of the adder/subtractor;
- inputting a product output (F.sub.R.B.sub.R) from the multiplier into the A input of the adder/subtractor and initiating a subtraction process;
- inputting the signal B.sub.R from the B.sub.R storage unit into the X and Y inputs of the multiplier and starting the multiplying process;
- inputting a shifted output of the adder/subtractor into the A input of the adder/subtractor and initiating an addition process;
- storing a combined output from the adder/subtractor in the L.sub.N temporary storage unit;
- inputting a shifted product output (B.sub.R.B.sub.R /C) into the A input of the adder/subtractor;
- inputting the signal F.sub.R from the F.sub.R storage unit into the X and Y inputs of the multiplier and starting the multiplication process;
- inputting a shifted product output (F.sub.R.F.sub.R /C) into the B input of the adder/subtractor and initiating an addition process;
- inputting a signal, K.sub.I, from a N position K.sub.I storage unit into the Y input of the multiplier and starting the multiplication process;
- inputting a combined output from the adder/subtractor into the A input of the adder/subtractor;
- inputting a signal, L.sub.D, from a L.sub.D temporary storage unit into the B and -B inputs of the adder/subtractor and initiating a subtraction process;
- inputting a shifted combined output from the adder/subtractor into the A input of the adder/subtractor and initiating an addition process;
- inputting a combined output from the adder/subtractor into the L.sub.D temporary storage unit;
- inputting the signal B.sub.R from the B.sub.R temporary storage unit into the A input of the adder/subtractor;
- inputting a product output (K.sub.I.F.sub.R) from the multiplier into the -B input of the adder/subtractor and initiating a subtracting process;
- inputting the signal B.sub.R from the B.sub.R temporary storage unit into the X input of the multiplier;
- inputting the signal K.sub.I from the K.sub.I temporary storage unit into the Y input of the multiplier and initiating a multiplication process;
- inputting the signal from the first temporary storage unit into the B.sub.R temporary storage unit;
- inputting a combined output from the adder/subtractor into the first temporary storage unit;
- inputting a product output (K.sub.I.B.sub.R) from the multiplier into the -B input of the adder/subtractor;
- inputting the signal F.sub.R from the F.sub.R storage unit into the A input of the adder/subtractor and initiating a subtraction process;
- inputting a combined output from the adder/subtractor into the X input of the multiplier and the F.sub.R storage unit;
- inputting a shifted quotient outputs from the divider (DL.sub.D /L.sub.N) into the A input of the adder/subtractor;
- inputting the signal L.sub.N from the L.sub.N storage unit into the numerator input of the divider;
- inputting the signal L.sub.D from the L.sub.D storage unit into the denominator input of the divider and initiating a divide process;
- inputting the signal K.sub.I from the K.sub.I storage unit into the B and -B inputs of the adder/subtractor and initiating a subtraction process;
- inputting a shifted combined output from the adder/subtractor into the A input of the adder/subtractor and initiating an addition process;
- inputting a combined output from the adder/subtractor into the K.sub.I storage unit;
- inputting the signal B.sub.R from the B.sub.R storage unit into the Y input of the multiplier and initiating a multiplication process;
- and
- returning to step 2 and repeating the steps N times using F.sub.R from the F.sub.R storage unit to provided N K.sub.I 's in the storage unit.
31 more elements
In a process of analyzing human speech utilizing an all-zero lattice filter wherein the forward residual signal, F.sub.R, and backward residual signal, B.sub.R, inputted to each of the N stages of the filter are utilized to derive a partial correlation coefficient for each of the N stages, a method of deriving the partial correlation coefficient from the signals F.sub.R and B.sub.R comprising the steps of:
- (a) multiplying the signals F.sub.R and B.sub.R to produce a first product;
- (b) filtering the first product to produce a numerator;
- (c) multiplying the signal F.sub.R by itself to produce a second product;
- (d) multiplying the signal B.sub.R by itself to produce a third product;
- (e) combining the second and third products to produce a sum signal of the products having a magnitude approximately one half of the magnitude of the sum of the two products;
- (f) filtering the sum signal to produce a denominator;
- (g) dividing the numerator by the denominator to produce a quotient;
- and
- (h) filtering the quotient to produce the partial correlation coefficient.
6 more elements
Dependencies are inferred from the claim text.