It’s useful for both, actually. It’s basically depth perception for both senses, since we’ve got 2 ears and eyes. At first, you’re hearing/seeing from two points. Then when you tilt your head, you’re rotating those two points on a different plane, giving you a different frame of reference.
It’s hearing, not sight.
Tilting their head means the sound hits each ear just a little bit off, and those milliseconds difference let’s them locate the sound in 3d
It’s useful for both, actually. It’s basically depth perception for both senses, since we’ve got 2 ears and eyes. At first, you’re hearing/seeing from two points. Then when you tilt your head, you’re rotating those two points on a different plane, giving you a different frame of reference.