Patent ID: 8526599

Claim:
An input/output apparatus comprising: a speaker configured to output audio based on a voice-receiving signal; a microphone configured to produce a voice-transmitting signal based on gathered audio; a mute signal input portion configured to output at least one of a speaker mute signal for muting the speaker and a microphone mute signal for muting the microphone, the speaker mute signal and the microphone mute signal being produced via an operation of a user; an adaptive filter circuit configured to produce a pseudo echo signal and output a residual signal produced based on the pseudo echo signal and an amplified voice-transmitting signal, the pseudo echo signal being produced from the voice-receiving signal and a transfer coefficient which expresses audio transfer properties between the speaker and the microphone, the amplified voice-transmitting signal being produced by causing a microphone amplification circuit to amplify the voice-transmitting signal; and a control circuit configured to stop output of the residual signal from the adaptive filter circuit when the speaker is muted according to the speaker mute signal outputted from the mute signal input portion or when the microphone is muted according to the microphone mute signal outputted from the mute signal input portion.