REAR SEAT DISPLAY DEVICE

A rear seat display device is provided in a vehicle at a position viewable from a rear seat of the vehicle. The rear seat display device includes a display, a built-in speaker, and a controller that (i) acquires a signal relating to control of a sound to be output to a vehicle speaker mounted in the vehicle from an in-vehicle audio device, the vehicle speaker being a different speaker than the built-in speaker, and (ii) controls a sound to be output from the built-in speaker based on the signal relating to the control of the sound.