A figurine is mounted on a shoe. A first rendering instruction hooking section is set to a first mode to hook a screen rendering instruction issued by a virtual machine application in a virtual machine. Then, the right transducer of the center speaker is energized to emit an acoustic ping signal, the transducers of the left and right speakers are utilized to detect the ping signal, and lapse of time between emission of the ping signal by the right transducer and detection of the ping signal by the transducers of the left and right speakers is measured. In one embodiment, the memory cells can be third dimension memory cells.