Echo canceller with double talk detector

摘要

The echo canceller of the present invention comprises a means for estimating an echo gain from a reception signal level and a transmission signal level; a first level calculating means (5) for calculating logarithmically converted power of a reception signal level; a second level calculating means (16) for calculating logarithmically converted power of a transmission signal level; an echo gain estimation means (19) for estimating an echo gain based on the reception signal level and the transmission signal level; and an echo level estimating means (18) for adding the estimated echo gain to said reception signal level to obtain an estimated echo level, a third level calculating means (6) for calculating logarithmically converted power of a residual signal level; and a comparison means (19) for comparing the estimated echo level with the residual signal level after the echo cancellation; wherein the echo of the reception signal contained in the transmission signal is canceled when said estimated echo level exceeds the value obtained by adding a margin to the residual signal level.