A system processes an audio signal and a video signal by using different devices, thereby preventing a so-called lip sync error. The processing time (represented by processing-time information) from the start of reception of a supplied video signal in a video processor apparatus to the start of displaying a video corresponding to the video signal on a display screen of a display device is acquired in an amplifier device from the video processor apparatus through a control signal line. In accordance with the acquired processing time, a delay processor delays processing of an audio signal supplied from the delay processor.