Please state in which country your phrase tends to be used, what the phrase is, and what it should be.
Example:
In America, recently came across “back-petal”, instead of back-pedal. Also, still hearing “for all intensive purposes” instead of “for all intents and purposes”.
I think you might be on the wrong side of the argument here, as others are pointing out the ‘quiet’ part of that sentence isn’t meant to be low volume, but more along the lines of secret or unspoken, and the ‘out loud’ part doesn’t mean volume, it means ‘spoken’.
If it helps, it’s like when someone says something they were thinking and goes ‘oh no, did i say that out loud?!’… They’re not specifically worried about how loudly they said it, but that they said it audibly at all when they meant to only think it.