When the argument gets louder, try getting quieter. It’s weirdly hard to keep yelling at someone who’s whispering.

Shouting needs a partner. Volume climbs because each person is matching the last, and the content stopped mattering several rounds ago. Dropping your own level breaks the rhythm, and the other person usually follows without deciding to, because it is strange to keep yelling into a quiet voice.

Try it in the next argument that is escalating. Speak more slowly and more softly than feels natural, and do not announce that you are doing it. This is not a trick for winning; it just buys back the conditions where talking is possible.