The repetition of similar vowel sounds within lines is

The repetition of similar vowel sounds within lines is called "assonance". It occurs when the vowel sounds in words that are close together are repeated, but the consonant sounds are different. For example, "fleet feet sweep by sleeping geese" has a repetition of the "ee" sound in "fleet", "feet", "sweep", and "sleeping". This repetition of vowel sounds can create a pleasing musical effect in poetry or prose.