Birds can communicate with each other through different noises that they make with their Sound Boxes.
Birds' do not have voice boxes like us, but have sound boxes. These “sound boxes” are double pronged, allowing the birds to combine two sounds at the same time instead of just one. We humans only have one tube in our voice box; thus we cannot make such complicated sounds.
Male birds also use their voices to attract females to breed or to call out their locations to tell others where they should not come. The Three-wattled Bellbird uses its throat muscles to create a sound that is very loud that can be heard from half a mile away.
Birds also attract mates by calling out with their clear voices. Some birds, such as Mockingbirds, know hundreds of songs, while others know only one or two.