I would prefer to play Carl, rather than Drake; however - I have gone for both. Each button plays both of their character's lines - with a small delay inbetween. For technical reasons... there is a short wait before the recording actually starts... it gives a better sound; however - I'm sure that you can clip the wait off the recording. (I just haven't <--- because I am lazy.)
I really hope I get a part. I used Audacity to add the echo effect. (It's actually echo AND reverb.) Oh, and because drake is an adult; I changed the pitch to slightly lower. If I do get the part, if you don't want me to, I can make it so that there is no echo / reverb. English? Yes.