What do we call a repeated sound in poetry, typically at the beginning of words?

The correct choice refers to alliteration, which is characterized by the repetition of initial consonant sounds in close proximity within a phrase or line of poetry. This literary device is often used to create rhythm, enhance the musical quality of poetry, and emphasize particular themes or emotions.

For instance, in the phrase "wild and whirling words," the repeated 'w' sound draws attention and adds a lyrical quality to the expression. Alliteration can also help to unify a poem and make it more memorable for the reader or listener.

The other options represent different poetic devices. Assonance involves the repetition of vowel sounds within words close to each other. Personification gives human qualities to non-human entities, and onomatopoeia refers to words that imitate the natural sounds associated with the objects or actions they refer to, such as "buzz" or "clang." Each of these serves distinct functions in poetry but does not pertain to the repetition of initial consonant sounds.