Loud threats are usually a sign someone’s out of real options.

People with actual power tend to be quiet, because they can simply act. Noise comes in when acting is not available, so the volume has to do the work instead, and the bigger the threat the less there usually is behind it. Recognizing this changes what a shouting person feels like. It stops looking like danger and starts looking like a problem they cannot solve.

Next time someone escalates at you, listen for what they are actually able to do. Often the answer is not much. Stay calm, do not match the volume, and respond to the real situation rather than the performance in front of it.