use vocaroohttp://vocaroo.com/
guessing this is ithttp://www.youtube.com/watch?v=TYJzcUvS_NU
we cannot help you if the only way you can describe it is by using onomatopoeia.
UNLESS IT'S DUBSTEP LOLOLOLOL
http://www.youtube.com/watch?v=Iof5pRAIZmwdon't care if it's not the one you want. still damn inspirational.