Do you guys know why an Owl needs to have silent flight?
Tip: It is not for the obvious reason of not scaring its prey.
An owl does not hunt by sight as people believe…they hunt by hearing.
The ears of an owl are not on the same axis or level. They are “off centre” which is why most owls have a flat face. The slightest noise that a mouse or other prey makes, get amplified through the “dish” of an owl’s face to its ears. The one ear hole is much higher on the head than the other one. The moment that the sound waves hit the ears at the same time, the owl knows that its nose points exactly to the prey.
One will also see that the claws of an owl are held directly in front of its face when it strikes.
That is so that the claws are in line with the sound waves.
Therefore, an owl needs silent flight so as to not interfere with its hearing while it glides down to strike.
The long and short of how an owl hunts!

The 2  Eagle Owl species in South Africa are the only owls that do not go into “tonic immobilisation” when you fold their wings and turn them on their backs. They bite the hell out of you and grab hold of you with their claws.
Tip: Dont ever let an Eagle Owl grab hold of your arm!