Why is silent flight useful even if a mouse never hears the owl coming?

Answer: Keeps prey sounds audible

Keeps prey sounds audible ✓ — Right. One major hypothesis is self-masking: wing noise can cover the faint rustles, chewing, or movements an owl uses to locate prey. That means silent flight is not only a stealth cloak for the mouse's ears; it is also a hearing aid for the owl's ears. The neat twist is that both explanations can be true in different hunting situations.

Aims ears more precisely — This is close to the hearing topic, but the quiet wing does not physically aim the ears. Barn-owl experiments show prey can be located in total darkness by hearing alone, so the problem is protecting that sound channel. If the owl's own wings are noisy, they can mask the rustle it needs to aim at. Silence is partly about not deafening yourself.

Amplifies tiny rustles — Quiet flight does not amplify the mouse's rustle like a microphone. The self-masking idea is about signal-to-noise: reducing the owl's own wing sound leaves the existing prey sound easier to hear. That distinction matters because silence is subtractive here. The owl is not making the target louder; it is making its own noise smaller.