Mercedes-Benz has developed a safety system that helps to protect the ears of passengers just before a collision. When the car detects an unavoidable crash is imminent PRE-SAFE®Sound will activate the vehicle’s sound system and plays a short sound. Called “pink sound” or “pink noise,” this signal plays at about 80 decibels, which is roughly equivalent to the level of noise at the side of a busy road. The signal causes a natural reflex in the ear, called the stapedius reflex, to activate, protecting the eardrum and reducing the damage loud noises produced by the crash can cause to your hearing.