Why is katakana used for the onomatopoeia/sounds in the background? In Japanese, katakana is used for loan words/foreign words, but it shows up a lot in backgrounds of manga as what seems to be onomatopoeia. Is this manga-specific, and where did it originate?



The center white katakana on the bottom panel seem to be "fuaaaaa", for instance.
Using onomatopoeia to stress sound effects in literature is not manga-specific or even comic-specific. For example, 1966's Batman TV series or even Nickelodeon's The Fairly OddParents had readily available audio to match their onscreen text with emphasis. But several cultures have their own origins. Tracing back when this particular artistic/literary device caught on would be pretty exhaustive, if even credible at all.