a lot depends on the situation, a raised voice can have a positive effect in the right situation, when I'm out in the field (or moors or woodland) working my dogs that I consider quite well trained and they're running to close to boxed in birds, the whistle sometimes isn't enough but a raised voice of either "down" or "heel" grabs their attention and snaps their attention back to me.
"never argue with stupid people, they may drag you down to their level and then beat you with experience"..Mark Twain
Ruby's d.o.b. 21/6/2011,,Lyharr Grouse Shot d.ob. 7/01/2015