Onomatopoeia:
Onomatopoeia is a figure of speech in which the sound of the words or phrases suggests the sense. The use of words whose sound imitates the sound of the thing being named. For example, the pronunciation of words like hum, buzz, clang, boom, hiss, crack, and twitter suggests their meaning. The value of onomatopoeia as a poetic device becomes evident when sound echoes sense throughout an entire phrase or line:
The murmurous haunt of flies on summer eves.
And the silken, sad, uncertain rustling of each purple curtain.
The moan of doves in immemorial elms,
And murmuring of innumerable bees.
"Tis the night of doom," say the ding-dong doom-bells.