Echo cancelling device

摘要: PURPOSE:To make an echo signal cancelling characteristic flat and increase a howling margin by performing compensation with voice switches respect to frequency for which sufficient quantity is not attained because the power spectrum of transmission small. CONSTITUTION:A inverse estimating circuit 605 insertion losses 602 608 are added newly device. The digitized in A/D converting 601 inputted only at time control from transmission/reception discriminating 108, estimates this calculates coefficient filter, realizes characteristic, supplies 608. On basis 605, set so as have signal. Voice 603 609 controlled 108 inserted reception side time.