I grew up with a shouty mum. If she had a grievance with me from anything minuscule to major, her default was to shout about it. I remember the resentment, embarrassment and distress I felt by being shouted at.
Think about it logically. If shouting actually worked, you would only need to do it once and then nothing for ever?! So in short, shouting doesn't work. It may work well on rare occasion but only if it's so unusual it would be something to really take notice of.
Shouting only really works for the shouter, because they are stressed (probably about unrelated things) and shouting makes themselves feel better. They are letting out tension and stress at the expense of the recipient. Kids are an easy target for shouters.
I'd start with pausing for breaths between sentences when you find yourself starting to shout. Or keep it short. One or two shouted sentences might come out, but there's no need to carry it on into a tirade. It can be reigned in.
Another one (harder to do an not a long term solution, but effective for training every now and again) is forcing yourself to whisper your annoyance. It's really difficult but you will realise how much energy it takes to shout and how much of a conversation you will shout.
Sometimes, it's helpful to recognise that you can't deal rationally (ie without shouting) with a situation, and (depending on how old the DCs are and what the situation is) it's best return to the subject when you have calmed down after a few minutes/later on.
Kids won't always remember the content of the shouting (unless it's combined with unpleasant personal put-downs, in which case they will likely remember most of that) but they will remember the shouting and volume and anger in general. We as adults know that we are "only" raising our voices and are otherwise in control of ourselves, but kids don't necessarily know this. They don't know what other lack of control might follow. Shouters can look very frightening to a kid.
However a PP has said that her kids don't remember her as a shouter (which is really good). I think if the habit is broken, then the shouting times become faded, perhaps to the point of forgotten, but if the shouting isn't curtailed (and exchanged for healthier communication habits) at some time during the childhood then it will still be memorable into adulthood.