| 摘要 |
PURPOSE:To prevent the howling with no reduction of the speaker output by obtaining the correlation degree between sound signals of two transmission lines and removing the howling component according to said correlation degree. CONSTITUTION:The sound output signal of a preamplifier 2 is supplied to a correlation circuit 11 together with a sound signal obtained by delaying the output of a preamplifier 6. Thus a correlation output is obtained. This output is supplied to a multiplication circuit 12 together with a sound signal obtained by delaying the sound output signal of the preamplifier 6 by the circuit 10. Thus a multiplication signal proportional to the correlation output and the sound signal level is obtained. This multiplication signal and the sound output signal of the preamplifier 2 are supplied to a subtraction circuit 9. Thus a signal component corresponding to the multiplication signal is extracted out of the sound output signal of the preamplifier 2. Thus the howling component is removed without reducing the speaker output. |
