| 摘要 |
PURPOSE:To quickly capture the degree of an unharmonious sound without being affected by a measuring person by counting the number of waves of a microphone output voltage after the sounding of a buzzer to measure the maximum on positive and negative sides in the microphone output voltage for each wave until the number of microphone output voltage waves further reaches the specied value N (2<=n<30). CONSTITUTION:When a counter 13 reaches the specified counting point of pulses, a switch 14 is closed to actuate counting circuit sections 17-21 at the point and the maximum of voltages of amplifiers 15 and 16 is held in maximum measuring/holding circuit sections 22-31 for each wave sequentially to the number n. Groups of maximum of pulses (a1, a2... and a5) and (b1, b2... and b5) on positive and negative sides of an output voltage of a microphone amplifier 12 are obtained. These values enter an arithmetic circuit seection 32 to automatically compute R+=amax-amin, R-=bmax-bmin, amax=max(a1, a2... and a5), amin=min(a1, a2... and a5), bmax=max(b1,b2... and b5) and bmin=min(b1, b2... and b5). Here, R1 and R2 are automatically calculated by putting R1=max(R+, R-) and R2{(R+)<2>+ (R-)<2>}<1/2>. |
