To my dear friend, “jewish source”, with all due respect….
BEKOL ROM does NOT mean screaming you way through Pesukei Dezimrah and Shema – show me in Halacha that you are supposed to do that.
Everyone will agree that BEKOL ROM means davening out loud – loud enough at a comfortable level for all those surrounding you. So, screaming during davening shows that he is more important than those around him.