The correct answer is onomatopoeia.
Onomatopoeia is a word that imitates, suggests or resembles the sound it makes or describes. The word itself comes from the Greek where it means 'making or creating names'.
The reader can almost hear the sounds as he reads the words, the sounds are made in a way that they resemble the actual, real sound.
Some examples of onomatopoeia are: roar, chirp, miaow, oink tic tock, bark purr etc.
'Tra-la--la' and cheeped is examples of onomatopoeia because the words imitate the sounds the bird makes.
