Loud is a poem about a women being able to express her feeling without being oppressed and not being able to speak her mind. This poem also has ironic simplicity of rhyme as it reduces the pervasive ideology of organised religion.
"In the wind and rain, wailing, uttering lightning." ~ This could suggest that she has alot of power as lightning power and strength and she is in the same position.
This is an aphorism as the same message is being shown throughout the poem.
Harpie ~ "Her scream was a huge bird that flew her away into the dark; each vast wing was a shriek." (Harpie is a freek mythalogical monster, a bird with the face of of a woman)