The sound you hear is NOT an effect, it is the shutter opening and closing (the click) and the mirror motor moving the mirror up and down (the whir). Non-SLR cameras don't have the mirror since they don't have an optical viewfinder, so they have the sound effect to sound more like a Real Camera when you push the button. If you think the camera is too loud, there is personal function 21 you can enable to operate the mirror motor at a slower speed in single shot mode, which quiets things considerably.