US Patent 8238547 Sound pickup apparatus and echo cancellation processing method

A sound pickup apparatus selecting one of a plurality of microphones and performing echo cancellation processing for a plurality of microphones with an echo canceller to output a sound. The sound pickup apparatus sets a “learning mode” when the power supply is turned on, outputs a calibration sound from an echo cancellation calibration sound generator via a speaker, detects an echo at that time with a microphone and obtains an echo cancellation use parameter canceling the echo.