To provide an echo canceler whose determination accuracy of double-talk is high, whose determination accuracy of the double-talk is high even if a voice power ratio between a received voice and a transmitted voice is the same, and which can detect a speaker and the double-talk adapting to an environment noise.
An echo canceler is provided with a transfer function estimating means 48 by which a transfer function by reverberations of a room is estimated from an output of a speaker 9 when sounds are acquired by a microphone 10, a filtering means 49 for estimating by the transfer function estimating means 48, a subtracting means 51 subtracting a signal by the filter means 49 from a signal from the microphone to obtain a subtracting signal, a backup memory means 50 periodically storing a coefficient of the filter means 49, a howling detecting means 47 detecting a howl in a signal from a remote end speaker, a first attenuating means 52 attenuating a voice from the remote end speaker to be outputted to the speaker, and a second attenuating means 53 attenuating a voice of a near end speaker from the subtracting means 51 to the remote end speaker to be transmitted.
KAWASAKI NAOTO
SASAKI HIDEAKI
KOGA JUNICHI
YAMASHITA KENSUKE
Tomoyasu Sakaguchi
Hiroki Naito