Answer:
They create a regular rhythm.
Step-by-step explanation:
Assonance and Consonance are the repetition of vowel sounds.
For example: consider this phrase:
Men set the wedding bells.
The sound of the short vowel "e" is being repeated. This gives the poetry a pleasing rhythm to it.
Hope this helps!
For more information: check out "What are Assonance and Consonance: A Literary Guide for Students and Teachers" by OSU School of Writing.