Using Interjections - Word Emotions
First the definition:
Hmm, I don't know. When writing, I'll often use those sort of interjections to denote natural language.
Now, I use those 'word emotions' as part of a longer piece of text, but they're certainly used.
The revelation clearly shocked the young jedi, whose eyebrows arched upwards. "I... Uhh... Wow." He stammered a bit as his brain struggled to catch up with this development. "Alright, so let me get this straight. You've been having relationship trouble, your mom died, and some guy who's been creeping on you since you were eight years old convinced you that killing children could fix all your problems? That's messed up."
I rarely use them but I also hate seeing them exaggerated with many repeated letters. Its like the difference between saying "Very very" rather than just "Very".
These can be great to use but they depend on your audience otherwise they may not be taken well or in the way it was intended. This is more true in this sensitive world of political correctness.