The sound effects will have been adding from modding the phone. The user will have simply selected the sounds they want whenever the phone is opened or closed. I've modded mine to have it play different startup and shutdown sounds .
__________________ K800i, Focus 1.0 Mod Pack, Peter's HiFi Acoustics, 2.9 Cam Driver 35 FPS video recording
You have to patch your phone to use .ELF files. There is an elf file that allows you to use any .mp3 sound as sliding sounds for your W580i. search google for soundslide.elf.