Abstract: Characteristics of noise contained in input signals of a plurality of microphones are adjusted to be equal to each other at each frequency, and an input signal of a microphone identified to be a microphone through which a speaker has input uttered speech from among the microphones subjected to adjustment of the noise characteristics is switched to a signal to be transmitted to a person on another end of call.

Abstract: Characteristics of noise contained in input signals of a plurality of microphones are adjusted to be equal to each other at each frequency, and an input signal of a microphone identified to be a microphone through which a speaker has input uttered speech from among the microphones subjected to adjustment of the noise characteristics is switched to a signal to be transmitted to a person on another end of call.

Abstract: Disclosed is an echo canceller 10 including: mixers 11A and 11B each to mix output signals outputted by speakers 7FL and 7FR with an instructed mixing ratio, and to generate reference signals for microphones 8A and 8B; an adaptive filter 12 to generate two pseudo echo signals from the two reference signals generated by the mixers 11A and 11B; subtractors 13A and 13B to subtract the two pseudo echo signals from input signals from the microphones 8A and 8B, and to generate two echo eliminated signals; residual echo detectors 14A and 14B to detect residual amounts of echo remaining in the echo eliminated signals obtained from the microphones 8A and 8B; and a mixing ratio changer 15 to instruct a change of the mixing ratios of the mixers 11A and 11B in accordance with the residual amounts of echo.

Abstract: Disclosed is an echo canceller 10 including: mixers 11A and 11B each to mix output signals outputted by speakers 7FL and 7FR with an instructed mixing ratio, and to generate reference signals for microphones 8A and 8B; an adaptive filter 12 to generate two pseudo echo signals from the two reference signals generated by the mixers 11A and 11B; subtractors 13A and 13B to subtract the two pseudo echo signals from input signals from the microphones 8A and 8B, and to generate two echo eliminated signals; residual echo detectors 14A and 14B to detect residual amounts of echo remaining in the echo eliminated signals obtained from the microphones 8A and 8B; and a mixing ratio changer 15 to instruct a change of the mixing ratios of the mixers 11A and 11B in accordance with the residual amounts of echo.