Those horns were first called simply accessory horns. In '39 Chevy started calling them Town & Country horns as Sparky noted. They are quite loud when working properly. You might want to find or make the support brace that connects to the bracket between the horns and runs to the firewall. Over time the flexing without the brace can cause work hardening of the bracket. You can see the brace here in this pre restoration pic of my '38.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.