How do you edit your vocals like this on Cool Edit Pro?

Ok so you know how Lil Wayne and Nicki Minaj make their vocals repeat in some of their songs? LIke in Nicki Minaj's song "Did It On 'Em" when she repeats her L's. Like when she says "L- l- l- l- l- l- l- emme shake it off" how do you make your vocals repeat like that? And when she says 'P- p- p- p- put ya number 2's in the air if ya did it on 'em". Like do they do that when they record it or is it an effect? If it is an effect, can you tell me how to do it? Thanks.