It’s a bit more complicated: if you’re dealing with the sounds it’s transcription, if you’re converting from writing system into another it’s transliteration.
So for example, what you did is transliteration. But if you were to record some Japanese guy speaking and wrote it down (in kanji+kana, Latin, or even IPA), or if you handled how it’s actually spoken, it would be transcription.
One of my favourite instances of adaptation got to be Ted Woolsey’s “son of a submariner! They’ll pay for this…”, for the English localisation of Final Fantasy III / VI.
In the game, Kefka (the villain) is saying this as the heroes escape him, but the original only says “ヒーーー くっそー!このかりは必ず返しますよ!”; literally “heeee shit! I will definitively return this debt” or similar. However:
So, translating it as simply “hey you!” or similar would mutilate the original, by removing the rudeness. But at the same time, Woolsey couldn’t use “shit” or “crap” or similar. So he looked at the context:
So Woolsey went with “son of a submariner!”, something he likely made up on the spot. And you know what? It’s perfect - it’s completely on-character for Kefka to insult people in such a weird way.