In the sentence
why is it 音を表したことば rather than 音を表していることば?
I'm reading https://japanese.stackexchange.com/a/11976 but I'm not sure if this sentence produces a resultative state (like the answer suggests). I've also read that た can also indicate a continuative state/action like ている does, and the justification is that in relative clauses the past tense can be neutralized, but I don't seem to understand this correctly. I've found this example (from https://japanese.stackexchange.com/a/3362)
A person wearing (in-progress) a white-collar shirt
A person who "wore"/put-on (and still has on) a white-collar shirt.
A cat who is currently fat
A cat who got/become (and still is) fat
but I'm not sure if this applies to every verb or just some verbs (maybe 表す?). Also, does the verb being transitive/intransitive affect the meaning of た as non-past?