We derive the word assonance from the Latin word ‘assonare’, which means ‘To answer with the same sound’. Assonance relies on the same type of vowel grapheme, not necessarily the same letter, and does not rely on rhyme. The mechanism used in this technique is a resemblance in the sound of vowels in syllables, words, phrases, or sentences placed closely together. They do not need to be side by side, just close enough to register the resemblance. The resemblance can occur at the beginning, the end, on stressed syllable, on unstressed syllable, or in any words, phrases, or sentences in the syllables, words, phrases, or sentences involved.
The effect is to mirror or change the mood of a poem in order to match the subject and have the words resonate with the content of the lines or sentences in which it occurs. The words become more meaningful, more obvious, and it encourages the reader to look at, sound out, and think about these words and their placement. Using this technique will encourage repeated reading of the group of words. Assonance highlights the craft of poetry by calling attention to the language itself, resulting in a deeper and more meaningful poem.
Assonance provides poetry with rhythm, forcing the reader to slow down and speed up at the same time. The slowing occurs because you must stop to think about the word’s juxtaposition to gain a comprehension of what the poet is trying to get at. When easy to read, or pleasurable to pronounce, the reading speed will increase for a group of words. This slowing and speeding is pleasurable to read and will gain you more readers.