HOWLING SUPPRESSING DEVICE

摘要

PURPOSE:To suppress surely howling by frquency-dividing an input signal into plural signals and comparing the level of each divided signal to detect the band where howling takes palce and to attenuate a signal level passing through the band. CONSTITUTION:The signal from an input terminal 1 is branched into two, one is delayed for an optional time by a delay circuit 2, frequency-divided at plural BPF3-5 and applied to attenuators 13-15. The others branched signal is frequency-divided at BPF6-8, the divided signal is applied to average energy measuring circuits 9-11, a short time average enerby of each divided signal is measured to input to a control circuit 12. The control circuit 12 compares the average energy of each divided signal to detect whether or not any howling takes palce and to control the attenuation extent of the attenuators 13-15 by the detected result. The signals passing through the attenuators 13-15 controlled by the control circuit 12 are summed at an adder 16 and the howling is suppressed to output it to an output terminal 17.