A method and system for authenticating print media includes providing a digital memory physically associated with a holder of print media, and storing data in the digital memory, which data is adapted to be authenticated to allow use of the print media. The game console switches the communication channel for the audio inputoutput device from the game program to a voice recognition engine without interrupting the execution of the game program on the console. The combustion liner comprises a one-piece casting construction. The distance between the first and the second recording layer is about 31 to 40 \u03bcm. Each first upper surface is inclined in the second direction so as to be lowered from a central part toward interfaces between each first upper surface and the second upper surfaces adjacent to each first upper surface.