The information processing device includes a communicator 31 for communicating with a vehicle 40 and a mobile device operated by a user, and a controller 33 for controlling the communicator 31, and the controller 33 acquires position information indicating the position of the vehicle 40 and position information indicating the position of the mobile device via the communicator 31, and outputs sound data for identifying the vehicle 40 from the communicator 31 to the mobile device in accordance with the distance between the position of the vehicle 40 and the position of the mobile device.