How does the reader know zaroffs is an intelligent and sophisticated man?

The author uses direct representation to tell us that Zaroff is sophisticated.

In a cultivated voice marked by a slight accent that gave it added precision and deliberateness, he said, "It is a very great pleasure and honor to welcome Mr. Sanger Rainsford, the celebrated hunter, to my home....Rainsford's first impression was that the man was singularly handsome.