Dear Student,
Birds have the most hearing receptors in their brains and they have asymmetrical (different on each side) ear openings. One opening is higher and one is lower to aid in locating prey or predator. Because of the difference in the location of the openings, a bird will hear a sound at two slightly different times. The bird uses that very small difference – a 30 millionth of a second, in some cases – to figure out the "left/right" location of its prey.
Several birds uses echolocation as bat do, to detect the things in their path
Regards..