In a long argument, the person who talks once, late, and clearly usually ends it.

Volume loses its meaning quickly in a long disagreement. After a certain number of exchanges everyone has stopped listening and started waiting, and the argument runs on momentum rather than content. A single clear statement, made once, lands in a room that has run out of noise.

If you are in something that has been going round for hours, stop adding to it. Work out the one sentence that actually contains your position, and wait for a gap. Say it plainly, once, then let the silence hold rather than defending it immediately.