Described herein are systems, methods, and apparatus for determining audio context between an audio source and an audio sink and selecting signal profiles based at least in part on that audio context. At step S302, since a conveying path sensor 111 in an optional paper feed unit 101 does not detect residual paper, the CPU 202 notifies the CPU 201 that it is in a residual paper check start instruction waiting mode. A plurality of metal lines are then formed to electrically connect the two silicon based materials such that the LED chip can be mounted on the reflective cavity and electrically connected to the corresponding electrodes of the silicon-on-insulator substrate by the metal lines.