Silence Once Begun by Jesse Ball is one of my favorite books. I don't know how else to describe the principal narrator's voice, but I'm looking for anything that sounds similar. From the first page:
A First Telling of the Story
Oda Sotatsu was a young man in October of 1977. He was in the twenty-ninth year of his life. He worked in an office, an import/ export business owned by his uncle. They principally sold thread. To do this, they bought thread also. Mostly for Sotatsu it was buying and selling thread. He did not like it very much, but went about it without complaint. He lived alone, had no girlfriend, no pets. He had a basic education and a small circle of acquaintances. He appears to have been well thought of. He liked jazz and had a record player. He wore simple, muted clothing, ate most meals at home. The more passionately he felt about a subject, the less likely he would be to join a discussion. Many people knew him, and lived beside him, near him but few could say they had any sense of what he was really like. They had not suspected that he was really like anything. It seemed he merely was what he did: a quiet daily routine of work and sleep.
by Stupidprinny