Onomatopoeia is used throughout Hatchet. Onomatopoeia is the use of a word that imitates the natural sounds of something. It's a really neat tool because it creates a sound effect that attempts to mimic the thing being described. This will often make the description more expressive and/or interesting. It's also an effective tool to use with young readers because it very effectively makes a description easier to understand. Additionally, it draws readers in because it attempts to target a sense other than vision. Paulsen was likely very intentional about frequently using this literary device because of his young reading audience. Additionally, his protagonist is in a situation in which listening to things is just as advantageous as seeing environmental factors. The following is a good example from the end of Chapter 4. Notice the "hisses" and "blurks."
Here, at first, it was silent, or he thought it was silent, but when he started to listen, really listen, he heard thousands of things. Hisses and blurks, small sounds, birds singing, hum of insects, splashes from the fish jumping—there was great noise here, but a noise he did not know, and the colors were new to him, and the colors and noise mixed in his mind to make a green—blue blur that he could hear, hear as a hissing pulse-sound and he was still tired.
Then readers hear the "buzzing" insects in Chapter 5.
Then the bird started again, and some kind of buzzing insect, and then a chattering and a cawing, and soon there was the same background of sound.
Brian will eventually become good at hearing the slithering and brushing noises that could endanger him.
Then he heard the slithering. A brushing sound, a slithering brushing sound near his feet—and he kicked out as hard as he could . . .
Chapter 10 has a good water sound with the word "sloshing."
Whatever it was it stopped making that sound in a few moments and he thought he heard something sloshing into the water at the shoreline . . .