I would just be so angry if i saw a person slap their bird, even with huge macaws its still unacceptable!!! I usually whisper to my screaming macaw and after a few minutes <sometimes about 20 mins>he starts to whisper back. My soon to be ex husband had me give my OWA to my parents when he was in his 30's due to screaming, I wept every day and realized that it was the stress of living with my husband that made Loki scream. As everyone says, birds vocalize, isn't that part of the reason we are so drawn to them?????