No bank robbery is complete without the "Everybody lie down..." speech. You could be in the safety of your living room, and you'll still feel the fear of the bank customers and employees as the hooligans wave their guns around. Criminal voices evoke fear, and no matter how brave you are, once you hear them, self-preservation instincts kick in hard.
It can be the classy, calm, deceiving voice of a white-collar trickster or the scary, brute grunts of the muscle-bound thug. Whichever tone the criminal voice comes in, you know the character means business.
Criminal voices are often identified with villains, and for a good reason. Who steals from you and uses a squeaky voice? Nobody! It's the go-to voice for narrations, audiobooks, and other story-related media when they want to portray a character who's up to no good.
The white-collar con artist is often smooth, convincing, and reassuring, putting you in a false sense of security. You just never see it coming because the character seems sophisticated, classy, and mysterious. There is also the criminal that sounds threatening and angry. You can immediately tell that your life (or at least your health) is in grave danger at that time if you don't follow instructions.
In any story, the hero is as good as their villain. Creating a criminal persona laden with a criminal voice is a very important aspect of the story. The wittier or dangerous the villain is, the more invested the audience will be in the hero’s victory over them.