Sound devices are resources that authors use in order to convey a meaning or an experience through the use of sound. These include devices such as alliteration, assonance and rhyme.
<em>Ex.</em> From somewhere far beyond, the flag of fate's caprice unfurled, (the repetition of the "f" sound).
Imagery refers to the use of vivid descriptions in order to add depth to a work. Authors who use imagery use descriptions in order to create an image in our mind through our senses.
<em>Ex.</em> The girl ran her hands on a soft satin fabric. (sense of touch)