The natural term you will here in casting is “make it your own”. Make it your own means that you have permission to add a little bit here and there. But beyond that, if you don’t have that permission to make it your own, doing uttering and muttering (adding a word or sound) is something you can always do and it doesn’t change the script. You didn’t technically just change the script but you just kind of personalized it a little bit more. And they won’t even know why you’re so great! They add a lot of personality it makes a huge difference. The whole goal is to have you BE YOU through saying the lines. That is hosting, 101 through graduation… Be you saying whatever you going to do!