Sometimes, the most eloquent means of expression is to use words that aren't actually words at all.
Then of course, there's always the classic Toot, Whistle, Plunk and Boom.
And nothing beats a gratuitous URKK!! (Or a Ker-Sploosh! by the way)
SLAM! (He's okay, folks!)
A little bit SPLASH, a whole lotta CHOMP!
And finally: QUAAA??