What do sound devices contribute to James McBride's work The Color of Water?

The Color of Water by James McBride
is an autobiographical story told by a son and his mother. The chapters alternate, and
each chapter is written in the voice either of Ruth or her son James. Your question has
to do with devices of sound, which are something generally more concentrated and
applicable to poetry than to prose writing. Onomatopoeia, assonance, consonance, rhyme,
and alliteration are the most common devices of sound; and a poet will use them to add
emphasis and meaning to the words he chooses.

In this case,
it is perhaps the dialect the characters use which is the most poetic element in this
story. Ruth, though she is white, speaks in the dialect of a black woman from the
projects. She speaks directly and colorfully. James, too, speaks in a dialect,
especially in his early years. Dialect is more about a rhythm than a sound, though, so
it must be said that sound devices have very little to do with this piece of
writing.