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 quiet. The old man's deafness is also a metaphor for this "nothing" that he speaks of.
Hemingway is rather dramatically making the existential, angst-filled point that after all is said and done--after the enthusiasm of youth is spent and a night in bed with a wife can no longer be had--when all that is left is individual despondency, what one wants is the quiet, light instead of dark, a place clean and pleasant, and something of your dignity even though dignity is not provided for.
The symbol of the old man's deafness and the metaphor of deafness are significant because they provide the undergirding imagery of Hemingway's message of despair after the youth and its energetic noise of living are gone, have faded into dull quietude, into "nada y pues nada y nada y pues nada."
It was the light of course but it is necessary that the place be clean and pleasant. You do not want music. Certainly you do not want music. Nor can you stand before a bar with dignity although that is all that is provided for these hours. What did he fear? It was not a fear or dread, It was a nothing that he knew too well. It was all a nothing and a man was a nothing too.