Which organ helps some animals in hearing?

Directions: Answer the given question based on the following passage:

Interesting facts about animals:

1. An amazing species of frog, named, Panamanian Golden Frog, does not possess ears, but they rather listen with the help of their lungs. Yes, those lungs multi-task for them in the most amazing way. These frogs are not the only species with the same functionality, but there are many fish that also hear in the same manner.
2. Did you know that a group of fish is called school, while a group of owls is called parliament.
3. A woodpecker can peck on wood 20 times per second. Their average total pecks are 8,000 to 12,000 a day.
4. Sharks, one of the largest species of fish, do not have bones in their bodies. Their skeleton is made of a cartilage (A flexible bone like men have in their ears and nose). An amazing thing about a Shark’s skeleton is that it can easily be crushed under its own weight, while on dry land.