<story><title>Pre-Safe Sound: Playing ‘pink noise’ in the split second before impact (2015)</title><url>https://www.mercedes-benz.com/en/mercedes-benz/next/connectivity/pre-safe-sound-playing-pink-noise-in-the-split-second-before-impact/</url></story><parent_chain></parent_chain><comment><author>ComputerGuru</author><text>This is a comment from Reddit on the same [0]; though I cannot vouch for its veracity, I found it interesting nonetheless:&lt;p&gt;Former Benz master tech here.&lt;p&gt;I&amp;#x27;ve spent a good bit of time diving into the nitty gritty of these systems.&lt;p&gt;It uses all of the vehicle sensors to determine crash logic.&lt;p&gt;You want to fire the pretensioners before the airbags if at all possible. This locks the occupants in a much more secure and predictable psition.&lt;p&gt;Accelerometers can determine if something like a rollover is in progress.&lt;p&gt;Heavy braking + high speed + sudden activation of the parking sensors indicates a crash before physical contact happens.&lt;p&gt;It can use the radar on distronic equipped cars to predict a crash.&lt;p&gt;If the vehicle is in a slide, and a sudden yaw correction happens, this means a collision has occurred, even if the airbag sensors haven&amp;#x27;t been triggered. This is useful because the airbag sensors are only good at detecting force in one dimension.&lt;p&gt;It&amp;#x27;s even possible for the vehicle to determine to fire the pretensioners but no airbags based on occupant size and weight (determined through seat&amp;#x2F;steering wheel position and capacitive mats in the seats) and impact vectors.&lt;p&gt;It will even do things like full field the alternator up to 18+ volts to slam the windows shut super fast in the event of a rollover.&lt;p&gt;The actual detection logic fills a 4&amp;quot; thick book.&lt;p&gt;It&amp;#x27;s a big reason those cars are so damn expensive.&lt;p&gt;Mercedes doesn&amp;#x27;t fuck around with safety.&lt;p&gt;If I had to be in a wreck, it would be in an S class. Hands down.&lt;p&gt;0: &lt;a href=&quot;http:&amp;#x2F;&amp;#x2F;www.reddit.com&amp;#x2F;r&amp;#x2F;todayilearned&amp;#x2F;comments&amp;#x2F;59qhaw&amp;#x2F;til_new_mercedesbenz_cars_will_play_a_short_blast&amp;#x2F;d9avtav&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.reddit.com&amp;#x2F;r&amp;#x2F;todayilearned&amp;#x2F;comments&amp;#x2F;59qhaw&amp;#x2F;til_ne...&lt;/a&gt;</text></comment>
<story><title>Pre-Safe Sound: Playing ‘pink noise’ in the split second before impact (2015)</title><url>https://www.mercedes-benz.com/en/mercedes-benz/next/connectivity/pre-safe-sound-playing-pink-noise-in-the-split-second-before-impact/</url></story><parent_chain></parent_chain><comment><author>codeulike</author><text>The interesting bit:&lt;p&gt;&lt;i&gt;If an impending collision is detected that would be expected to produce a loud crash, the vehicle’s sound system plays a short interference signal. This causes the stapedius muscle in the ears to contract, which for a split second changes the link between the eardrum and the inner ear and so better protects it against high acoustic pressures. Most importantly, the reflex reduces the damage to hearing.&lt;/i&gt;</text></comment>