How to set AIM 6 to change sound when i sign in/out but same im sound when i im somebody?

I want to change my aim sound so wheni sign in and sign out its a different sound. But when i im somebody it has the same sound i dont want that. I want the default sound.My sound for when i sign is a scream.But when i im someone i still hear the scream..I dont want that. I want the regular from before. Is there a way to keep the scream but when i im someone i hear the regular sound?