Jeta, I wasn't sure what you meant either, unless you're talking about analyzing poetry. In poetry, there's onomatopoeia [a-nǝ-ma-tǝ-'pi-ǝ], which are words that mimic natural sounds, such as "Whoosh!" for a sudden wind.
Also, if you were writing a poem about a snake, you might use lots of words with the "s" sound to mimic the hissing of a snake. It makes your poem more "snaky." By the way, the word "hiss" is onomatopoeic. When you say "hiss," it sounds like how an English speaker imagines a snake speaks.