Standing up for yourself doesn’t have to be loud. A steady “that doesn’t work for me” hits harder than yelling.

Volume is what people reach for when they doubt they will be taken seriously, and it usually undercuts the point. A flat, unhurried sentence carries more because it does not sound like it needs anything from the listener. Calm reads as certainty; shouting reads as negotiation.

Decide the sentence in advance and keep it to one line. Say it at normal volume, then stop talking and let the pause do the rest of the work. Repeating it once, unchanged, is more effective than escalating into an argument you did not want.