Written sound effects are familiar from Batman tv-series and of course super hero cartoons. If they are in language you're not that familiar with they may sound really funny or disturbing depending on your state of mind.

For example, I found shooting sound effects in the books by Frank Miller very confusing. My ear says that no automatic gun says: "Brekkk!"
Just to give you some Finnish example, we may write "nar nar" for creaking sound.