If there is danger of collision, Mercedes-Benz first uses a natural reflex to adapt your hearing to the noise expected to be made from the accident. This was nature's doing: a muscle in our ears called the stapedius reacts to loud noises as a reflex by contracting. As it contracts, the tiny muscle briefly changes the way the eardrum links to the inner ear and thus better protects it against high noise pressures. Mercedes-Benz uses this natural reflex as biomechanical hearing protection in the PRE-SAFE® Sound innovation, as accidents can produce sounds which some people may be particularly sensitive to. If danger of collision is detected, PRE‑SAFE® Sound therefore plays a brief noise signal over the vehicle's sound system. This can trigger the stapedius reflex and adapt the occupants' hearing accordingly. This may reduce the risk to the occupants' hearing.