Onomatopoeia (adjective onomatopoeic) is a Figure of speech to label the use of words to imitate the sounds they are describing. Words like 'Boom!' and 'Crash' are everyday examples, as is the child's word for an ambulance, 'Nee-naw', trying to imitate the sound of its siren. Advertisers often appeal to onomatopoeia: "Snap, crackle, pop" is a slogan based on the sound of a cereal reacting to milk. Comic strips and graphic novels oftern invent new words to communicate the sounds of their scenes, often the violent sounds: 'Ker-pow!' and 'Zap' are examples.
Poets often use onomatopoeia.
The quotation given for alliteration, "the stuttering riflesâ€™ rapid rattle", followed by "the monstrous anger of the guns", is an example of more than alliteration: it is also an example of Owen was trying to say what a battlefield of the first World War sounded like; in my view, he is remarkably successful in distinguishing between the deep, dull boom of heavy artillery ("monstrous anger of the guns") and the crisper, sharper crackling of the ordinary soldiersâ€™ rifles. Onomatopoeia is often reinforced by alliteration.