Can you make your voice sound tougher on audacity?

Hey me and my bro are rappin preparing for my mixtape,now I was
wondering if there's anyway I can make my brothers voice alil tougher
like a similarly to Dmx or ja rule,you know that raspy voice when they
spit,when my bro raps,he makes his voice get raspy but he doesn't have
that much of a deep voice,how can we make his voice deep and raspy on
audacity? Thanks :)