Patent ID: 8644496
Filing Date: 2014-02-04
Classification: H04M

Abstract:
1. An apparatus for suppressing an echo signal included in a measured signal corresponding to a measured sound, the apparatus being capable of coupling to a sound input device for receiving the measured sound and a sound output device for outputting a sound associated with a reference signal, the apparatus comprising: a part which performs each transformation of both the measured signal and the reference signal in a time domain to both the measured signal and the reference signal in a frequency domain; a part which obtains each value of a ratio and a correlation between the measured signal and the reference signal in the frequency domain, the ratio and the correlation being obtained directly from the measured signal and the reference signal in the frequency domain; a part which derives a coefficient decided in accordance with a larger value that is selected from the value of the ratio and the value of the correlation; a part which obtains an estimated value of the echo signal on the basis of a product of the coefficient and the reference signal in the frequency domain; and a part which suppresses the echo signal in the measured signal by subtracting the estimated value of the echo signal from the measured signal, respectively in the frequency domain.