A sound recording apparatus is provided which is HDMI-connected to a camera and another device, which outputs a video image signal from the camera to the other device without processing, and which outputs to the other device, without degradation, an audio signal recorded separately from the camera. A sound recording apparatus is HDMI-connected to a camera and a backup image recording apparatus. The sound recording apparatus includes an HDMI receiver that receives an HDMI signal transmitted from the HDMI-connected camera, a controller that embeds an audio signal which is input from a microphone which is connected to the apparatus in an audio channel portion of the HDMI single, and an HDMI transmitter that outputs to the backup image recording apparatus the video image signal included in the HDMI signal and the audio signal embedded by the controller.