It is because their voice boxes are that way. Are voice boxes make certain sounds, and their voice box makes those types of sounds. Also, their shape could echo and turn the sound into the audible sound you hear.
Animals do make sounds but it's not all of the animals that make sounds.
animals make the sounds they do is just like human languages.... for example a whistle may mean they are calling for their family. The animals make the sounds they do because they all need to communicate with each other.
There are a lot more animals than just 2 that make unusual or loud sounds.
Animals make a variety of sounds, such as barks, meows, chirps, roars, and howls, to communicate with each other. These sounds can vary depending on the species of animal and the situation they are in.
animals make certain sounds because that is how they communicate with each other. for example a hawk, a bear, a lion etc.
Thats like saying how do we humans make diffrent sounds if you think about it how do you make diffrent sounds? and thats your answer!
bleet
They make sounds like cats. They hiss or screach like other animals too.
birds lions crickets
Listen to some animals! See what sounds you like - growls, howls, grunts, whatever. It's your language. Make whatever sounds good to you. Animals make an awful lot of different sounds.
Turkeys are revered for their gobbling sounds.
Most animals have vocal cords more or less complex than ours, therefore they can make different noises. Ours are advanced enough to make sounds LIKE them but not exactly.