They're different in different languages, but I'm looking for the name of the category of those words.
For example, a sound of dog's barking: "woof-woof". But in Russian it's "ghav-ghav";
A sound of cat: "meow". But in Japanese it's "nya".
Also various sounds that are used in comics: "boing", "bang", "poof", "ka-pow", etc.
EDIT:
These words are called "Onomatopeic"