Did you know that the car horn actually predates the car? How can that be, you ask? Well technically there was not a “car” horn until the automobile was invented, but earlier transportation methods needed some sort of noisemaking device to alert pedestrians and others that you were coming through.
In the early 1800s, there were laws requiring a man to travel in front of steam carriages waving a red flag and honking a horn (much like the trucks and cars that precede oversized trucks on the highways). This soon went out of style and the noisemakers quickly became attached to the vehicle rather than separated out on the street. These noisemakers were available in multiple types, including bells, whistles, and actual horns.
What we think of as a traditional horn did not became popular until the early 1900s. The invention of the assembly lined Ford Model T with its classic Aoogah sound is what many people have in mind when they think of retro horns (and this horn sound is still available and quite popular!) However, the original classic horn was actually called the Klaxon.
Thorough the years, car manufacturers have continued to try to engineer the car horn to perfection. They continually adjust the sound level as well as the tone. Manufactures have to balance the decibel levels to make car horns audible to drivers listening to the radio in their tightly sealed vehicles, but not so loud that they deafen nearby pedestrians. The notes car horns play also vary, but nowadays with electrical horn technology, horns can play multiple notes and even songs!