Behold, the loudest siren ever built! Built between 1942 and 1957, Chrysler and Bell Laboratories worked together to create a siren that could outdo everything else. Boasting a deafening sound output of 138 decibels at 100 feet, a single Chrysler could fill the role of tens or even hundreds of smaller sirens. Back in WW2 and the Cold War, expense was secondary to making sure everyone could hear the warning.