The next time you jump at the sound of thunder or feel an adrenaline rush when you hear the new active valve performance exhaust on the 2019 EcoBoost-equipped Mustang, thank your prehistoric ancestors. It’s called an autonomic response, and it traces back to ancient humans who successfully learned to react quickly to loud and powerful sounds, like the roar of a lion or the crash of a tree. Over time, this fight-or-flight response to avoid danger was passed along in our DNA and hardwired into our minds and bodies. Eons later, that connection between sounds and our emotional reactions caught the attention of an 18th century music critic named Friedrich Marpurg, who was among the first in modern times to document different sounds and the emotional responses they elicit. Today, modern sound engineers tap into those very same concepts when they create sounds for everything from movies and music, to cars and cellphones – and even appliances.