An echo processor includes an echo suppression amount decider which
compares a state of an outgoing input signal to be sent including an echo
with a state of an incoming input signal and calculates an echo
suppression amount based on the comparison, a time-frequency transformer
which transforms the outgoing input signal in the time domain into the
frequency domain, thereby generating an amplitude spectrum and a phase
spectrum, a noise-spectrum estimator which estimates a noise spectrum
from the amplitude spectrum, a mixer which mixes an amount of the noise
spectrum based on the echo suppression amount with the amplitude
spectrum, and a frequency-time transformer which generates an outgoing
output signal including a noise in the time domain on the basis of the
amplitude spectrum, with which an amount of the noise spectrum is mixed
by the mixer, and the phase spectrum, and outputs the outgoing output
signal.