| 摘要 |
PURPOSE:To evaluate characteristics with due regard to the sense of a human being by removing a component exerting no effect on the evaluation of the characteristics of an apparatus to be measured from the signal of the difference between a measuring test signal and the corresponding output signal. CONSTITUTION:A measuring test signal is supplied to an apparatus 51 to be measured through an input terminal and the signal deformed corresponding to the characteristics of the apparatus 51 to be measured is outputted. The test signal is controlled by a characteristic separating circuit 53 to be sent to an adder circuit 54 as a subtraction signal along with the output signal of the apparatus 51 and the difference between both signals is calculated. Further, in an invalid component detecting circuit 56, the invalid component for masking considering the hearing characteristics of a human being and the evaluation of characteristics due to the min. audible limit curve is calculated on the basis of the test signal and removed from the signal from the circuit 54 by an invalid component removing circuit 55. By this constitution, the number of elements measured when characteristics are evaluated by a measuring means 58 is reduced and evaluation accuracy can be enhanced. |
