Why are these senses most appropriate in a poem about evening?

The "sound of sense" is a literary theory in which specific syllables and sounds are used to express the subject of a poem in a visceral way. For example, in the poem "Mowing," Frost selects certain terms (such a "whispering") in order to convey an aural sense of the swishing motion of the scythe as it cuts the hay. Frost is very concerned with the clarity and expression of his poetry, particularly in terms of the topic that he is discussing. By using the "sound of sense," Frost is able to layer additional meaning onto each of his works. Instead of absorbing the meaning of the poem solely through visual means, a reader is able to feel and even hear the meaning of the poem on a deeper level.