Practice these TOEFL iBT listening tests to help you score high in the TOEFL Listening Section. Check the correct answers and audio transcripts below. This video is in the series of NEW TOEFL iBT Tests: https://www.youtube.com/playlist?list=PL2jvSGmpWX1UMjbc8Onae7i-R6Z8VcPbU.
Questions 6 through 11. Listen to a lecture in a zoology class.
(professor) Today, we’ll be talking about how different types of animals hear. Many animals have sense organs that allow them to process sound waves. However, the sense organs are structured and function in very different ways in different types of animals.
First, we’ll look at the hearing abilities of some examples of insects and amphibians. Let’s look now at an example of an insect. A cricket's a type of insect, and it has thin membranes that vibrate when sound hits them. The thin “hearing" membranes on a cricket are found on the side of each front leg. On other insects, these vibrating membranes can be found on various other body parts.
Now, let’s look at an example of an amphibian. . . . The frog’s a good example of one. The frog has large disks that serve as eardrums. These disks are located farther back on the head, behind each eye. The disks, or eardrums, behind each eye vibrate when sound hits them. So you see that the frog has large disks on its head that serve as eardrums, unlike the cricket that I talked about earlier, which is able to hear by means of vibrating membranes on the side of each front leg.
Now, let’s look at the hearing of birds and bats. Birds have external auditory canals along the sides of the head. The auditory canal on a bird is merely an opening that leads to the middle and inner ear, and this auditory opening on a bird is usually covered with feathers.
Birds lack auricles, which are external portions of the ear that protrude from the body.
Bats are not birds; they're mammals. And like most mammals, they have auricles. You can see the large auricles on the bat, the part of the ear that protrudes from the bat’s head. Bats are dependent on their hearing to navigate in the dark; they have very effective auricles that move to enhance their ability to pick up sound waves as they enter the ear. So we’ve seen that birds and bats have different ways of hearing because bats are mammals so they have auricles. But birds are not mammals, so they don’t have auricles. They have auditory canals instead.
Now, let’s look at some other types of mammals, the elephant and the rabbit. Mammals are the only animals that have auricles, and elephants and rabbits are mammals, so they have auricles.
The auricles of the African elephant are the largest of any animal, and rabbits have auricles that are unusually large in proportion to their bodies. These large auricles allow heat to escape the body and assist these animals in cooling off in hot weather.
Now let me switch gears and talk for a moment about écholocation. Some animals are dependent on their hearing to navigate in the dark. The process that they use is called écholocation. Animals that use écholocation produce sounds and then listen for echos as the sound waves they have produced are reflected off of objects around them. They use écholocation to determine when objects are in their path and how far away the objects are. Bats and whales are two animals that navigate using écholocation, and there are many more.
Today we’ve discussed the types of hearing organs that various animals have. You should be familiar with animals that have external vibrating membranes, animals that have auditory canals, animals that have auricles, and animals that use écholocation. If you understand these various types of hearing organs, then you understand the important points of this lecture.
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Correct Answers:
6. D
7. Cricket: Membranes on legs
Frog: Disks behind eyes
Bird: Auditory canals
8. A
9. C
10. B
11. A & B
