The effects of the double noseband on attitude
A properly adjusted double noseband encourages the horse to keep its mouth closed. This is an incentive because the noseband should not be so tight that the horse cannot move.
By maintaining this working attitude, the horse is protecting its mouth. By opening the mouth, the bit acts directly on the corners. If he keeps his mouth closed, he keeps a certain sensitivity of the commissure. This way, he is more attentive to the hand and maintains a good working attitude. When properly adjusted, the double noseband should allow you to work with a horse that is relaxed, chews his bit and becomes light in his movements.
Nosebands, like snaffles, provide comfort for your horse, as long as they are properly adjusted.