Onomatopoeia

Onomatopoeia is defined as a word, which imitates the natural sounds of a thing. It creates a sound effect that mimics the thing described, making the description more expressive and interesting.
For instance, saying, “The gushing stream flows in the forest” is a more meaningful description than just saying, “The stream flows in the forest.” The reader is drawn to hear the sound of a “gushing stream” which makes the expression more effective.
In addition to the sound they represent, many onomatopoeic words have developed meanings of their own. For example, “whisper” not only represents the sound of people talking quietly, but also describes the action of people talking quietly.
Examples :

• The buzzing bee flew away.
• The sack fell into the river with a splash.
• The books fell on the table with a loud thump.
• He looked at the roaring sky.
• The rustling leaves kept me awake.

The different sounds of animals are also considered as examples of onomatopoeia. You will recognize the following sounds easily:

• Meow
• Moo
• Neigh
• Tweet
• Oink
• Baa

reference : http://literarydevices.net/onomatopoeia/