My whistles are necessary when in the field training my dog or actually hunting. Whistles are used to recall your dog back to you or letting them know to go no further. I blow once on my whistle to have my dog go no further. I blow twice on my whistle to have my dog return back to me. At that time I can release him to begin hunting once again. Using a whistle is important in controlling your dog’s movement while hunt training or hunting. If your dog obeys the whistle commands he will be much more successful during his hunting. Also during hunt testing. The whistle is your only means of control over your dog’s movements when he is out of range of your voice. It is a critical piece of equipment when in the field with your dog.