<u><em>The speaker of a poem is sometimes the poet.</em></u>
Explanation:
Assuming the poet or the writer is always the <u>speaker of the poem</u> may be incorrect because there can be a variety of instances in which the poet detaches him/herself from the <u>speaker's voice</u> and conveys the message through a <u>different person</u>.
Nevertheless, the poets can also be the <u>speakers of the poem</u> when it comes to representing specific emotions and personal views.