Wordology, Pink Noise

Mercedes provides your ears with an extra layer of audio protection called pink noise designed to keep your hearing intact by the extremely loud sounds typically associated with a vehicle crash.
The crunching metal, breaking glass, and the explosive deployments of airbags can hit 165 decibels or higher, and has the potential to permanently damage a passenger’s hearing. Pink noise, which Mercedes calls “Pre-Safe Sound” is unique in that its power is inversely proportional to the signal. When it hits the ear, it triggers muscles in the ear to contract by reflex, automatically bracing the inner ear and eardrum for the extremely loud noise of the crash by reflecting some of the sound before it reaches the point where it could cause problems.

Once the vehicle’s sensors have detected that a collision is unavoidable, a comprehensive system of safety features is activated within the short time before an impact occurs. It takes just 150 milliseconds to deploy the reversible seat belt tensioners and other safety features. The duration of a human blink is 100 milliseconds.