The first 30 minutes utilize a 28 Hz low-frequency hum—similar to earthquake vibrations—designed to induce actual nausea, dizziness, and vertigo in the viewer.
Gaspar Noé used specific psychological triggers to manipulate the audience's physical reaction to the film: irreversible 2002 movie link
Which are you located in? (Streaming rights vary significantly by region). The first 30 minutes utilize a 28 Hz