| 摘要 |
PURPOSE:To make it possible to discriminate immediately whether the input signal is a sound signal or a model signal, by using a forecasting circuit dependent upon the linear forecasting method. CONSTITUTION:Sound forecasting circuit 600 adapted to a sound signal and data forecasting circuit 610 adapted to a data signal forecast the next sample value on the basis of past sample values and the statistical character of sound or data. The input signal from terminal 601 is input to circuits 600 and 610 and subtractors 620 and 630, and the difference between the output of circuit 600 and the input signal is operated by subtractor 620, and the error signal is input to smoothing circuit 650. Meanwhile, the difference between the output of circuit 610 and the input signal is operated by subtractor 630, and the error signal is input to smoothing circuit 650. Energy of the input signal is smoothed by circuits 640 and 650, and respective outputs are compared with each other by comparator 660; and when the output of circuit 640 is larger than that of circuit 650, a signal to report that the input signal is a data signal is output to output terminal 602. |
