In Hemingway's "A Clean, Well-Lighted Place" what is the significance of the old man's deafness?

an old man who sat in the shadow the leaves of the tree made against
the electric light. In the day time the street was dusty, but at night the dew settled the dust
and the old man liked to sit late because he was deaf and now at night it was quiet and he felt
the difference. The two waiters inside the cafe knew that the old man was a little drunk, and
while he was a good client

The old man's deafness is
significant because Hemingway uses him and the deafness as a symbol for the "nothing"
that the older waiter discourses about when he, himself, is all alone in the...