100 Animal Sounds-High

Animal Sounds FOCUS Question How do different animals make sounds?

Talking and Singing Humans You probably spend a lot of time talking every day. Humans speak to communicate information. We also sing, both for fun and to entertain others. That's why we talk and sing, but did you ever wonder how we make sounds? Humans have special body parts to make these sounds. We use our larynx (LAIR-inks), or voice box, which contains two bands of tissue called vocal cords. As we exhale, the vocal cords vibrate, or move back and forth, and make sounds. Other animals also have special body parts for making sounds.

Singing Gibbons Gibbons are small apes that make loud, piercing calls. Gibbons sing to announce their home area, attract a mate, and communicate with their family. Gibbons' vocal cords are similar to those of humans. When the vocal cords vibrate, they move air molecules, which produces sound. Like opera singers with high voices, gibbons can change the shape of their mouth, tongue, and throat to make sounds that are very loud and high-pitched. They also use more force when they breathe out. You can hear the results in their famous ear-splitting calls. Do You Know? A gibbon's "song" can travel over a mile through jungles.

Purring Cats Purring is a common sound, but it's also a mystery. Scientists know how cats purr, but they're not sure why. Cats don't choose to purr— it's more like a twitch. Purring is caused by muscles that control the cat's vocal cords. The muscles contract, or get tighter, in rhythm. This quickly opens and closes the space between the vocal cords. With each breath, air hits the vibrating muscles and vocal cords. The purring sounds that result are created very fast— 25 to 150 times per second! To Purr or Not to Purr Not all cats can purr. House cats, bobcats, lynxes, and mountain lions can purr. Lions, tigers, leopards, and jaguars can't. But they can roar! All cats have a hyoid bone at the base of the tongue. Smaller cats have a stiff hyoid bone. Most big cats have a bendable one, which may allow them to roar.

Croaking Bullfrogs You're walking near a pond and hear a loud, deep gr-rum, gr-rum. That's the sound of an American bullfrog. Males croak to keep other males away and to attract mates. Females croak to let males know they're interested in them. Bullfrogs croak by forcing air out of their lungs through their larynx, which makes their vocal cords vibrate. The vibrating air molecules travel to a pouch of skin under the mouth, called the vocal sac, which makes the sounds louder. The large size of the vocal sac gives the air molecules lots of space to bounce around. Gr-rum! Gr-rum!

Singing Birds Songbirds are known for their amazing melodies. They may sing to find a mate or to guard their home area. Their songs may also alert each other to a predator or food source. Instead of a larynx, songbirds have a two-sided syrinx (SERE-inks). Both sides have thin layers of tissue, called membranes, that vibrate when air moves over them. The vibrations cause air molecules to move, sending out sound waves. Because the syrinx has two sides, songbirds can produce two different sounds at the same time. Stringing different notes together produces these birds' fancy songs.