Patent ID: 7092516

Claim:
An echo processor comprising: an echo suppression amount decider configured to compare a first threshold state level of a to-be-sent signal including an echo with a second threshold state level of an incoming receive signal within a reception path, and configured to calculate an echo suppression amount on the basis of the comparison; a time-frequency transformer configured to transform the to-be-sent signal in the time domain into the frequency domain, thereby generating an amplitude spectrum and a phase spectrum; a noise-spectrum estimator configured to estimate a noise spectrum from the amplitude spectrum of the to-be-sent signal; a mixer configured to mix an amount of the noise spectrum, based on the echo suppression amount, with the amplitude spectrum; and a frequency-time transformer configured to generate an output signal including a noise in the time domain on the basis of the amplitude spectrum, with which said amount of the noise spectrum was mixed by the mixer, and the phase spectrum, and configured to output the output signal.