Owls also have a moveable flap of skin controlled by muscles around the ear opening. This flap protects the ear and concentrates sound waves coming from behind. Finally, the owl's entire face acts as an outer ear. The face is two parabolic curves or satellite dishes that funnel sound to the ears. The facial feathers are also compact and tight to aid in the funneling process.
Ear tufts do nothing to improve hearing.
They are simply for defensive purposes. Ear tufts help the owl appear larger to ward off predators. The winners of the large eye contest are the owls. If we had eye proportional to those of the great horned owl, our eyes would be the size of grapefruit and weigh five pounds each. The difference between the hunted and the hunter is evident in the owls.