Gasper Noe's 2002 cult classic Irreversible features two very shocking scenes that gained the film notoriety. One of these is in a night clubnightclub where the main character is looking for someone who he ends up killing with a fire extinguisher (very gruesome scene). The whole scene was incredibly intensified by Thomas Bangalter's score mixed with the intense camera work.
Overall, the audience is left with a feeling of nausea, largely due to the well-designed soundtrack. It is really just a repetitive drone but it has an incredible effect of intensifying the gravity of the scene.