IN-VEHICLE COMMUNICATION SUPPORT SYSTEM

To provide an "in-vehicle communication support system" that cancels an unnecessary sound and relays an uttered voice. [0002] A first variable filter (31) receives a sound of a second seat audio source (1) as an input and generates a cancel sound for canceling the sound of the second seat audio source (1) at a first seat. The transfer functions of the first variable filter (31) and the second variable filter (36) are updated such that the level of a signal (Eu) obtained by subtracting the output of the auxiliary filter (35) that generates a correction signal for correcting the difference between the positions of the first seat microphone (9) and the first seat and the output of the second variable filter (36) that receives the sound of the first seat audio source (2) from the output of the first seat microphone (9) is minimized. While the level of the signal (Eu) exceeds a threshold, the signal (Eu) is relayed to the second seat as an uttered voice.