WIY – I have never seen an adam chashuv that doesnt raise his voice by davening
I’ve never seen one who does, and I had the zechus of sitting almost directly behind the hanholo when I was in Gateshead Yeshiva. I’ve seen R’ Nosson Tzvi ztz”l daven too and he never raised his voice. Same with R’ Yaakov Hillel and R’ Chaim Kanievsky. In fact you may wish to check your Mishnah Berurah (95, 5) who says that it is ossur to raise one’s voice during davening.