Spanish to English Art/Literary Poetry & Literature literature (expression/colloquialism)

I understand this expression, but for the life of me I can't come up with a way to phrase it in English that sounds good. It's being used in a book as a sort of double-entendre, i.e. first "speaking through the wound" is sort of like saying "that's your pain talking", i.e. the person is hurt (emotionally) and therefore saying things they might not otherwise say. But in this case, it is also (more) literal, in the sense that it is referring to a man who has a literal wound, which he got in a car accident that killed his wife and daughter.

So, he is alive and bitter and says mean, nasty things, because he is "hablando por la herida".

So far all I have been able to think is things like "a living, breathing wound" or "speaking through (one's) pain", both of which sound awful!

By the way, this is a text from Spain, but a Mexican friend tells me they say it there as well.

Ideas? Thanks!