The loudest person in the argument is usually the least sure they’re right.

Volume is often compensation. When someone is genuinely certain, they usually say the thing once and let it sit, because they are not worried about it falling over. The shouting comes in when the argument needs help standing, and loudness is the cheapest help available. It works on a room for about a minute and does nothing to the actual question.

In the next disagreement, watch for who repeats themselves louder instead of differently. If that person is you, try saying your point once at normal volume and letting the silence do the rest. If it cannot survive that, it may need better reasons rather than more force.