en.wikibooks.org/wiki/Japanese/Vocabulary/Onoma...
35 страниц этой ономатопии в мангах, обалдеть
fc03.deviantart.net/fs71/f/2012/159/3/8/japanes...

господи, вот оно - кладезь!
thejadednetwork.com/sfx/index/ka/

擬音語 giongo are words which describe a sound. Most giongo are written in katakana.
擬態語 gitaigo are words that describe an action, state, or emotion by an associated sound. They are typically written in hiragana.
In a typical style of Japanese writing giongo are written in katakana, while gitaigo are written in hiragana. However, this rule is not always observed. There are subtle nuances involved if you were to write one of these words in hiragana vs. katakana - katakana gives a kind of "harder" tone, while hiragana is "softer". Often, it is the author's discretion which to use.

блин, японцы такие японцы. звуки, которые звуки - катаканой. звуки, которые эмоции - хираганой. но не всегда и вообще )))