JPS6346876B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a simplified correlation coefficient measuring device.

The interaural cross-correlation coefficient has a close relationship with various properties such as the sense of distance, size, and clarity of the sound image. By measuring, it is possible to elucidate changes in the auditory sound image that cannot be explained by transmission frequency characteristics, reverberation time characteristics, diffuse sound energy characteristics, etc.

However, in normal correlation coefficient measurement, it is necessary to measure and normalize the autocorrelation coefficient after measuring the cross-correlation coefficients of two channels, which poses a problem in that the measurement requires a considerable amount of effort.

The present invention has been made in view of the above, and an object of the present invention is to provide a correlation coefficient measuring device that solves the above problems.

On the other hand, in order to solve the above problem, the applicant has already developed a sum signal of the third signal obtained by level matching the first input signal with the level of the second input signal and the second input signal. and the difference signal are individually rectified and smoothed, and then each is logarithmically compressed, and the logarithmically compressed difference signal is subtracted from the logarithmically compressed sum signal. A correlation coefficient measurement method is proposed to obtain a cross-correlation coefficient with a second input signal.

When using the above method, the correlation coefficient can be easily measured, but two logarithmic amplifiers are required for logarithm compression of the sum signal and difference signal, and the difference in the characteristics of the logarithm amplifiers causes a measurement error. Therefore, it is necessary to make the characteristics of the logarithmic amplifiers uniform, and also to suppress temperature drift and power supply voltage drift, which may make adjustment difficult.

An object of the present invention is to provide a correlation coefficient measuring device that does not require the above-mentioned adjustment.

The present invention will be explained below using examples.

FIG. 1 is a block diagram of one embodiment of the present invention.

in ₁ and in ₂ are input terminals, a first input signal x(t) is applied to the first input terminal in ₁ , and a second input signal y(t) is applied to the second input terminal in ₂ . ) is input.

1 and 2 are adders and subtracters, 3, 4, 5
and 6 are square circuits, 7, 8, 9 and 1
0 is the averaging circuit, 11 is 0.25(E-F)/
This is a microcomputer system that performs the calculation of √・.

First input signal x(t) and second input signal y
(t) is added by the adder 1, and the adder 1 adds the first input signal x(t) and the second input signal y.
(t) to obtain the sum signal A(t), the first input signal x(t) and the second input signal y(t) are subtracted by the subtracter 2, and the first input signal A difference signal B(t) is obtained by subtracting the second input signal y(t) from the input signal x(t), and the sum signal A(t) is squared through the squaring circuit 3 and the averaging circuit 7. The difference signal B(t) is configured to be averaged to obtain an output E, and the difference signal B(t) is squared and averaged through a squaring circuit 4 and an averaging circuit 8 to obtain an output F.

Further, the first input signal x(t) is squared and averaged through the squaring circuit 6 and the averaging circuit 10 to obtain an output C, and the second input signal y(t) is passed through the squaring circuit 5 and the averaging circuit 10 to obtain an output C. The output D is configured to be squared and averaged through an averaging circuit 9 to obtain an output D.

On the other hand, the outputs C, D, E and F are input to the microcomputer system 11 and are 0.25 (E-
F)/√· calculation is performed.

Therefore, E={()+()} ² , and F=
{x(t)-y(t)} ² , C is ² (), D is
²
(t).

Therefore, the calculation output of the microcomputer 11 is Therefore, the correlation coefficient Φ between the input signals x(t) and y(t) is output from the microcomputer 11.

Next, other embodiments of the present invention will be described.

FIG. 2 is a block diagram of another embodiment of the invention.

As in the case of one embodiment of the present invention, the first input signal x(t) and the second input signal y(t) are input to the adder 1 to obtain the sum signal A(t), Sum signal A
(t) is squared and averaged through the squaring circuit 3 and the averaging circuit 7 to obtain the output E, and the first input signal x(t) and the second input signal y(t) are sent to the subtracter 2. to obtain the difference signal B(t), and the difference signal B
(t) is configured to be squared and averaged through a squaring circuit 4 and an averaging circuit 8 to obtain an output F.

Further, the first input signal x(t) is configured to be squared and averaged through a squaring circuit 6 and an averaging circuit 10 to obtain an output C.

On the other hand, the outputs C, E and F are input to the microcomputer system 11' and are 0.25(E-F)/√
The calculation C{(E+F)×0.5−C} is performed.

So E = {() + ()} ² , F = {() - ()} ² , and C = ² ()
It is.

Therefore, the calculation output of the microcomputer 11' is Therefore, the correlation coefficient Φ between the input signals x(t) and y(t) is output from the microcomputer 11'.

As explained above, according to the present invention, since a logarithmic amplifier is not required, there is no fear of its drift, and there is no need for adjustment thereof, and the conventional drawbacks can be overcome.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention. Second
The figure is a block diagram of another embodiment of the present invention. 1...Adder, 2...Subtractor, 3, 4, 5 and 6...Squaring circuit, 7, 8, 9 and 10...Averaging circuit, 11 and 11'...Microcomputer system.

Claims (1)

[Claims] 1. A first means for squaring a first input signal and averaging it to obtain an output C; and a second means for squaring a second input signal and averaging it to obtain an output D. means for obtaining a sum signal of the first input signal and the second input signal; subtracting means for obtaining a difference signal between the first input signal and the second input signal; third means for squaring and averaging to obtain an output E; fourth means for squaring and averaging the difference signal to obtain an output F; A correlation coefficient measuring device comprising: arithmetic means for calculating 0.25(E-F)/√· using the output of the fourth means as input. 2. A first means for squaring the first input signal and averaging it to obtain an output C, an addition means for obtaining a sum signal of the second input signal and the first input signal, and a first input signal. and a second input signal; third means for squaring the sum signal and averaging it to obtain an output E; and squaring the difference signal and averaging it to obtain an output F. and a fourth means for obtaining 0.25×(E−
F)/√{(+)×0.5−}.