| 摘要 |
PURPOSE:To measure a mutual correlation coefficient between two channels easily and rapidly, by performing the logarithmic compression of the sum and difference signals of input signals and then by finding their difference. CONSTITUTION:Microphone input signals of two channels are inputted to adders 8 and 9 by way of attenuators 3 and 4, amplifiers 5 and 6, and phase inverter 7. Next, the output signals of adders 8 and 9 are logarithmically compressed by logarithmic amplifiers 12 and 13 after the full-wave rectification of full-wave rectifying circuits 10 and 11. The outputs of logarithmic amplifiers 12 and 13 are inputted to subtracter 14 to generate a DC output which corresponds to the dB difference between the effective value of the sum signal and that of the difference signal. At this time, the correlation coefficient is displayed on indicator 15 by adjusting the gain of amplifier 6 so that the difference in output level between logarithmic amplifiers 12 and 13 is zero. Thus, the mutual correlation coefficient in a field can be measured without measuring and standardizing cross correlation coefficients. |
