GUNDOG FIELD TRIALS & EVENTS
Only on unseen retrieves should it be necessary for you to use directional control to get the dog in the area of the fall ? once there, the dog should work on its own initiative to try to locate the retrieve.
Game-finding is paramount, so repetitive or inappropriate voice commands should be avoided.
The quieter you handle your dog, the more credit you will receive from the judges.
A whistle command is far less disturbing and certainly more audible to the dog when it is working at distance, whereas you would need a loud voice to have the same effect ? that would be classed as noisy handling.