THEATER CLOSE UP: UNCLE VANYA 9 p.m. on PBS (check local listings). This Richard Nelson production of the canonical Chekhov drama may be the most intimate version of the play available. The members of its ensemble, for the most part, deliver their lines in murmurs. “I happen to have a voice that can fill a theater rather easily,” Jay O. Sanders, who plays the title character in the production, told The Times last year. “But suddenly I was being told, ‘Don’t use that. Use your voice, but don’t do it to reach the audience; do it to reach the other people onstage,’ and the freedom of that has been extraordinary.” The result is a telling of the story that asks for careful listening , but rewards attentive audience members with the rare feeling that they’re flies on a wall of the forlorn 19th-century Russian estate where the story is set. In this production, the play is “clearer, truer and more comprehensible than it’s ever been before, as if it had always been operating on a frequency that you’ve only now been given access to,” Ben Brantley wrote in his review for The Times. “This,” he added, “is as naked and fully human an ‘Uncle Vanya’ as we’re likely to see.”